diff --git a/priv/guest_amd64_defs.h b/priv/guest_amd64_defs.h
index e3d23f0..5f95482 100644
--- a/priv/guest_amd64_defs.h
+++ b/priv/guest_amd64_defs.h
@@ -58,8 +58,8 @@
                            Long         delta,
                            Addr64       guest_IP,
                            VexArch      guest_arch,
-                           VexArchInfo* archinfo,
-                           VexAbiInfo*  abiinfo,
+                           const VexArchInfo* archinfo,
+                           const VexAbiInfo*  abiinfo,
                            VexEndness   host_endness,
                            Bool         sigill_diag );
 
diff --git a/priv/guest_amd64_toIR.c b/priv/guest_amd64_toIR.c
index 20298fc..2d8bd92 100644
--- a/priv/guest_amd64_toIR.c
+++ b/priv/guest_amd64_toIR.c
@@ -2275,7 +2275,7 @@
    .. -1(%rsp) should now be regarded as uninitialised.
 */
 static 
-void make_redzone_AbiHint ( VexAbiInfo* vbi,
+void make_redzone_AbiHint ( const VexAbiInfo* vbi,
                             IRTemp new_rsp, IRTemp nia, const HChar* who )
 {
    Int szB = vbi->guest_stack_redzone_size;
@@ -2320,7 +2320,7 @@
    by sorb, and also dealing with any address size override
    present. */
 static
-IRExpr* handleAddrOverrides ( VexAbiInfo* vbi, 
+IRExpr* handleAddrOverrides ( const VexAbiInfo* vbi, 
                               Prefix pfx, IRExpr* virtual )
 {
    /* --- segment overrides --- */
@@ -2445,7 +2445,7 @@
 
 static 
 IRTemp disAMode ( /*OUT*/Int* len,
-                  VexAbiInfo* vbi, Prefix pfx, Long delta, 
+                  const VexAbiInfo* vbi, Prefix pfx, Long delta, 
                   /*OUT*/HChar* buf, Int extra_bytes )
 {
    UChar mod_reg_rm = getUChar(delta);
@@ -2717,7 +2717,7 @@
    index and its multiplicand.  */
 static
 IRTemp disAVSIBMode ( /*OUT*/Int* len,
-                      VexAbiInfo* vbi, Prefix pfx, Long delta,
+                      const VexAbiInfo* vbi, Prefix pfx, Long delta,
                       /*OUT*/HChar* buf, /*OUT*/UInt* rI,
                       IRType ty, /*OUT*/Int* vscale )
 {
@@ -2905,7 +2905,7 @@
                        PUT tmpa, %G
 */
 static
-ULong dis_op2_E_G ( VexAbiInfo* vbi,
+ULong dis_op2_E_G ( const VexAbiInfo* vbi,
                     Prefix      pfx,
                     Bool        addSubCarry,
                     IROp        op8, 
@@ -3021,7 +3021,7 @@
                        ST tmpv, (tmpa)
 */
 static
-ULong dis_op2_G_E ( VexAbiInfo* vbi,
+ULong dis_op2_G_E ( const VexAbiInfo* vbi,
                     Prefix      pfx,
                     Bool        addSubCarry,
                     IROp        op8, 
@@ -3154,7 +3154,7 @@
                        PUT tmpb, %G
 */
 static
-ULong dis_mov_E_G ( VexAbiInfo* vbi,
+ULong dis_mov_E_G ( const VexAbiInfo* vbi,
                     Prefix      pfx,
                     Int         size, 
                     Long        delta0 )
@@ -3201,7 +3201,7 @@
                        ST tmpv, (tmpa) 
 */
 static
-ULong dis_mov_G_E ( VexAbiInfo*  vbi,
+ULong dis_mov_G_E ( const VexAbiInfo*  vbi,
                     Prefix       pfx,
                     Int          size, 
                     Long         delta0,
@@ -3288,7 +3288,7 @@
 
 /* Sign- and Zero-extending moves. */
 static
-ULong dis_movx_E_G ( VexAbiInfo* vbi,
+ULong dis_movx_E_G ( const VexAbiInfo* vbi,
                      Prefix pfx,
                      Long delta, Int szs, Int szd, Bool sign_extend )
 {
@@ -3392,7 +3392,7 @@
 }
 
 static 
-ULong dis_Grp1 ( VexAbiInfo* vbi,
+ULong dis_Grp1 ( const VexAbiInfo* vbi,
                  Prefix pfx,
                  Long delta, UChar modrm, 
                  Int am_sz, Int d_sz, Int sz, Long d64 )
@@ -3502,7 +3502,7 @@
    expression. */
 
 static
-ULong dis_Grp2 ( VexAbiInfo* vbi,
+ULong dis_Grp2 ( const VexAbiInfo* vbi,
                  Prefix pfx,
                  Long delta, UChar modrm,
                  Int am_sz, Int d_sz, Int sz, IRExpr* shift_expr,
@@ -3776,7 +3776,7 @@
 
 /* Group 8 extended opcodes (but BT/BTS/BTC/BTR only). */
 static
-ULong dis_Grp8_Imm ( VexAbiInfo* vbi,
+ULong dis_Grp8_Imm ( const VexAbiInfo* vbi,
                      Prefix pfx,
                      Long delta, UChar modrm,
                      Int am_sz, Int sz, ULong src_val,
@@ -3986,7 +3986,7 @@
 /* Group 3 extended opcodes.  We have to decide here whether F2 and F3
    might be valid.*/
 static 
-ULong dis_Grp3 ( VexAbiInfo* vbi, 
+ULong dis_Grp3 ( const VexAbiInfo* vbi, 
                  Prefix pfx, Int sz, Long delta, Bool* decode_OK )
 {
    Long    d64;
@@ -4164,7 +4164,7 @@
 /* Group 4 extended opcodes.  We have to decide here whether F2 and F3
    might be valid. */
 static
-ULong dis_Grp4 ( VexAbiInfo* vbi,
+ULong dis_Grp4 ( const VexAbiInfo* vbi,
                  Prefix pfx, Long delta, Bool* decode_OK )
 {
    Int   alen;
@@ -4248,7 +4248,7 @@
 /* Group 5 extended opcodes.  We have to decide here whether F2 and F3
    might be valid. */
 static
-ULong dis_Grp5 ( VexAbiInfo* vbi,
+ULong dis_Grp5 ( const VexAbiInfo* vbi,
                  Prefix pfx, Int sz, Long delta,
                  /*MOD*/DisResult* dres, /*OUT*/Bool* decode_OK )
 {
@@ -4664,7 +4664,7 @@
 
 /* IMUL E, G.  Supplied eip points to the modR/M byte. */
 static
-ULong dis_mul_E_G ( VexAbiInfo* vbi,
+ULong dis_mul_E_G ( const VexAbiInfo* vbi,
                     Prefix      pfx,
                     Int         size, 
                     Long        delta0 )
@@ -4707,7 +4707,7 @@
 
 /* IMUL I * E -> G.  Supplied rip points to the modR/M byte. */
 static
-ULong dis_imul_I_E_G ( VexAbiInfo* vbi,
+ULong dis_imul_I_E_G ( const VexAbiInfo* vbi,
                        Prefix      pfx,
                        Int         size, 
                        Long        delta,
@@ -5334,7 +5334,7 @@
 
 static
 ULong dis_FPU ( /*OUT*/Bool* decode_ok, 
-                VexAbiInfo* vbi, Prefix pfx, Long delta )
+                const VexAbiInfo* vbi, Prefix pfx, Long delta )
 {
    Int    len;
    UInt   r_src, r_dst;
@@ -7033,7 +7033,7 @@
    responsibility of its caller. */
 
 static 
-ULong dis_MMXop_regmem_to_reg ( VexAbiInfo* vbi,
+ULong dis_MMXop_regmem_to_reg ( const VexAbiInfo* vbi,
                                 Prefix      pfx,
                                 Long        delta,
                                 UChar       opc,
@@ -7183,7 +7183,7 @@
 /* Vector by scalar shift of G by the amount specified at the bottom
    of E.  This is a straight copy of dis_SSE_shiftG_byE. */
 
-static ULong dis_MMX_shiftG_byE ( VexAbiInfo* vbi,
+static ULong dis_MMX_shiftG_byE ( const VexAbiInfo* vbi,
                                   Prefix pfx, Long delta, 
                                   const HChar* opname, IROp op )
 {
@@ -7316,7 +7316,7 @@
 
 static
 ULong dis_MMX ( Bool* decode_ok,
-                VexAbiInfo* vbi, Prefix pfx, Int sz, Long delta )
+                const VexAbiInfo* vbi, Prefix pfx, Int sz, Long delta )
 {
    Int   len;
    UChar modrm;
@@ -7753,7 +7753,7 @@
 /* Double length left and right shifts.  Apparently only required in
    v-size (no b- variant). */
 static
-ULong dis_SHLRD_Gv_Ev ( VexAbiInfo* vbi,
+ULong dis_SHLRD_Gv_Ev ( const VexAbiInfo* vbi,
                         Prefix pfx,
                         Long delta, UChar modrm,
                         Int sz,
@@ -7938,7 +7938,7 @@
 
 
 static
-ULong dis_bt_G_E ( VexAbiInfo* vbi,
+ULong dis_bt_G_E ( const VexAbiInfo* vbi,
                    Prefix pfx, Int sz, Long delta, BtOp op,
                    /*OUT*/Bool* decode_OK )
 {
@@ -8115,7 +8115,7 @@
 
 /* Handle BSF/BSR.  Only v-size seems necessary. */
 static
-ULong dis_bs_E_G ( VexAbiInfo* vbi,
+ULong dis_bs_E_G ( const VexAbiInfo* vbi,
                    Prefix pfx, Int sz, Long delta, Bool fwds )
 {
    Bool   isReg;
@@ -8316,7 +8316,7 @@
 
 static
 ULong dis_cmpxchg_G_E ( /*OUT*/Bool* ok,
-                        VexAbiInfo*  vbi,
+                        const VexAbiInfo*  vbi,
                         Prefix       pfx,
                         Int          size, 
                         Long         delta0 )
@@ -8440,7 +8440,7 @@
                        PUT tmpd, %G
 */
 static
-ULong dis_cmov_E_G ( VexAbiInfo* vbi,
+ULong dis_cmov_E_G ( const VexAbiInfo* vbi,
                      Prefix        pfx,
                      Int           sz, 
                      AMD64Condcode cond,
@@ -8491,7 +8491,7 @@
 
 static
 ULong dis_xadd_G_E ( /*OUT*/Bool* decode_ok,
-                     VexAbiInfo* vbi,
+                     const VexAbiInfo* vbi,
                      Prefix pfx, Int sz, Long delta0 )
 {
    Int   len;
@@ -8648,7 +8648,7 @@
 //.. }
 
 static
-void dis_ret ( /*MOD*/DisResult* dres, VexAbiInfo* vbi, ULong d64 )
+void dis_ret ( /*MOD*/DisResult* dres, const VexAbiInfo* vbi, ULong d64 )
 {
    IRTemp t1 = newTemp(Ity_I64); 
    IRTemp t2 = newTemp(Ity_I64);
@@ -8698,7 +8698,7 @@
 */
 
 static ULong dis_SSE_E_to_G_all_wrk ( 
-                VexAbiInfo* vbi,
+                const VexAbiInfo* vbi,
                 Prefix pfx, Long delta, 
                 const HChar* opname, IROp op,
                 Bool   invertG
@@ -8748,7 +8748,7 @@
 /* All lanes SSE binary operation, G = G `op` E. */
 
 static
-ULong dis_SSE_E_to_G_all ( VexAbiInfo* vbi,
+ULong dis_SSE_E_to_G_all ( const VexAbiInfo* vbi,
                            Prefix pfx, Long delta, 
                            const HChar* opname, IROp op )
 {
@@ -8758,7 +8758,7 @@
 /* All lanes SSE binary operation, G = (not G) `op` E. */
 
 static
-ULong dis_SSE_E_to_G_all_invG ( VexAbiInfo* vbi,
+ULong dis_SSE_E_to_G_all_invG ( const VexAbiInfo* vbi,
                                 Prefix pfx, Long delta, 
                                 const HChar* opname, IROp op )
 {
@@ -8768,7 +8768,7 @@
 
 /* Lowest 32-bit lane only SSE binary operation, G = G `op` E. */
 
-static ULong dis_SSE_E_to_G_lo32 ( VexAbiInfo* vbi,
+static ULong dis_SSE_E_to_G_lo32 ( const VexAbiInfo* vbi,
                                    Prefix pfx, Long delta, 
                                    const HChar* opname, IROp op )
 {
@@ -8804,7 +8804,7 @@
 
 /* Lower 64-bit lane only SSE binary operation, G = G `op` E. */
 
-static ULong dis_SSE_E_to_G_lo64 ( VexAbiInfo* vbi,
+static ULong dis_SSE_E_to_G_lo64 ( const VexAbiInfo* vbi,
                                    Prefix pfx, Long delta, 
                                    const HChar* opname, IROp op )
 {
@@ -8841,7 +8841,7 @@
 /* All lanes unary SSE operation, G = op(E). */
 
 static ULong dis_SSE_E_to_G_unary_all ( 
-                VexAbiInfo* vbi,
+                const VexAbiInfo* vbi,
                 Prefix pfx, Long delta, 
                 const HChar* opname, IROp op
              )
@@ -8872,7 +8872,7 @@
 /* Lowest 32-bit lane only unary SSE operation, G = op(E). */
 
 static ULong dis_SSE_E_to_G_unary_lo32 ( 
-                VexAbiInfo* vbi,
+                const VexAbiInfo* vbi,
                 Prefix pfx, Long delta, 
                 const HChar* opname, IROp op
              )
@@ -8916,7 +8916,7 @@
 /* Lowest 64-bit lane only unary SSE operation, G = op(E). */
 
 static ULong dis_SSE_E_to_G_unary_lo64 ( 
-                VexAbiInfo* vbi,
+                const VexAbiInfo* vbi,
                 Prefix pfx, Long delta, 
                 const HChar* opname, IROp op
              )
@@ -8962,7 +8962,7 @@
       G = E `op` G   (eLeft == True)
 */
 static ULong dis_SSEint_E_to_G( 
-                VexAbiInfo* vbi,
+                const VexAbiInfo* vbi,
                 Prefix pfx, Long delta, 
                 const HChar* opname, IROp op,
                 Bool   eLeft
@@ -9117,7 +9117,7 @@
 /* Handles SSE 32F/64F comparisons.  It can fail, in which case it
    returns the original delta to indicate failure. */
 
-static Long dis_SSE_cmp_E_to_G ( VexAbiInfo* vbi,
+static Long dis_SSE_cmp_E_to_G ( const VexAbiInfo* vbi,
                                  Prefix pfx, Long delta, 
                                  const HChar* opname, Bool all_lanes, Int sz )
 {
@@ -9193,7 +9193,7 @@
 /* Vector by scalar shift of G by the amount specified at the bottom
    of E. */
 
-static ULong dis_SSE_shiftG_byE ( VexAbiInfo* vbi,
+static ULong dis_SSE_shiftG_byE ( const VexAbiInfo* vbi,
                                   Prefix pfx, Long delta, 
                                   const HChar* opname, IROp op )
 {
@@ -9945,7 +9945,7 @@
 /*---                                                      ---*/
 /*------------------------------------------------------------*/
 
-static Long dis_COMISD ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_COMISD ( const VexAbiInfo* vbi, Prefix pfx,
                          Long delta, Bool isAvx, UChar opc )
 {
    vassert(opc == 0x2F/*COMISD*/ || opc == 0x2E/*UCOMISD*/);
@@ -9988,7 +9988,7 @@
 }
 
 
-static Long dis_COMISS ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_COMISS ( const VexAbiInfo* vbi, Prefix pfx,
                          Long delta, Bool isAvx, UChar opc )
 {
    vassert(opc == 0x2F/*COMISS*/ || opc == 0x2E/*UCOMISS*/);
@@ -10033,7 +10033,7 @@
 }
 
 
-static Long dis_PSHUFD_32x4 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PSHUFD_32x4 ( const VexAbiInfo* vbi, Prefix pfx,
                               Long delta, Bool writesYmm )
 {
    Int    order;
@@ -10079,7 +10079,7 @@
 }
 
 
-static Long dis_PSHUFD_32x8 ( VexAbiInfo* vbi, Prefix pfx, Long delta )
+static Long dis_PSHUFD_32x8 ( const VexAbiInfo* vbi, Prefix pfx, Long delta )
 {
    Int    order;
    Int    alen  = 0;
@@ -10214,7 +10214,7 @@
 }
 
 
-static Long dis_CVTxSD2SI ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTxSD2SI ( const VexAbiInfo* vbi, Prefix pfx,
                             Long delta, Bool isAvx, UChar opc, Int sz )
 {
    vassert(opc == 0x2D/*CVTSD2SI*/ || opc == 0x2C/*CVTTSD2SI*/);
@@ -10262,7 +10262,7 @@
 }
 
 
-static Long dis_CVTxSS2SI ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTxSS2SI ( const VexAbiInfo* vbi, Prefix pfx,
                             Long delta, Bool isAvx, UChar opc, Int sz )
 {
    vassert(opc == 0x2D/*CVTSS2SI*/ || opc == 0x2C/*CVTTSS2SI*/);
@@ -10314,7 +10314,7 @@
 }
 
 
-static Long dis_CVTPS2PD_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTPS2PD_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10349,7 +10349,7 @@
 }
 
 
-static Long dis_CVTPS2PD_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTPS2PD_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10390,7 +10390,7 @@
 }
 
 
-static Long dis_CVTPD2PS_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTPD2PS_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10435,7 +10435,7 @@
 }
 
 
-static Long dis_CVTxPS2DQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTxPS2DQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                 Long delta, Bool isAvx, Bool r2zero )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10485,7 +10485,7 @@
 }
 
 
-static Long dis_CVTxPS2DQ_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTxPS2DQ_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                 Long delta, Bool r2zero )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10537,7 +10537,7 @@
 }
 
 
-static Long dis_CVTxPD2DQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTxPD2DQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                 Long delta, Bool isAvx, Bool r2zero )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10592,7 +10592,7 @@
 }
 
 
-static Long dis_CVTxPD2DQ_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTxPD2DQ_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                 Long delta, Bool r2zero )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10646,7 +10646,7 @@
 }
 
 
-static Long dis_CVTDQ2PS_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTDQ2PS_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -10694,7 +10694,7 @@
    return delta;
 }
 
-static Long dis_CVTDQ2PS_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTDQ2PS_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -10747,7 +10747,7 @@
 }
 
 
-static Long dis_PMOVMSKB_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVMSKB_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    UChar modrm = getUChar(delta);
@@ -10766,7 +10766,7 @@
 }
 
 
-static Long dis_PMOVMSKB_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVMSKB_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta  )
 {
    UChar modrm = getUChar(delta);
@@ -11221,7 +11221,7 @@
 
 
 /* Handle 128 bit PSHUFLW and PSHUFHW. */
-static Long dis_PSHUFxW_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PSHUFxW_128 ( const VexAbiInfo* vbi, Prefix pfx,
                               Long delta, Bool isAvx, Bool xIsH )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -11276,7 +11276,7 @@
 
 
 /* Handle 256 bit PSHUFLW and PSHUFHW. */
-static Long dis_PSHUFxW_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PSHUFxW_256 ( const VexAbiInfo* vbi, Prefix pfx,
                               Long delta, Bool xIsH )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -11323,7 +11323,7 @@
 }
 
 
-static Long dis_PEXTRW_128_EregOnly_toG ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PEXTRW_128_EregOnly_toG ( const VexAbiInfo* vbi, Prefix pfx,
                                           Long delta, Bool isAvx )
 {
    Long   deltaIN = delta;
@@ -11362,7 +11362,7 @@
 }
  
 
-static Long dis_CVTDQ2PD_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTDQ2PD_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -11397,7 +11397,7 @@
 }
 
 
-static Long dis_STMXCSR ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_STMXCSR ( const VexAbiInfo* vbi, Prefix pfx,
                           Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -11429,7 +11429,7 @@
 }
 
 
-static Long dis_LDMXCSR ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_LDMXCSR ( const VexAbiInfo* vbi, Prefix pfx,
                           Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -11547,7 +11547,7 @@
 }
 
 
-static Long dis_MASKMOVDQU ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MASKMOVDQU ( const VexAbiInfo* vbi, Prefix pfx,
                              Long delta, Bool isAvx )
 {
    IRTemp regD    = newTemp(Ity_V128);
@@ -11590,7 +11590,7 @@
 }
 
 
-static Long dis_MOVMSKPS_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MOVMSKPS_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    UChar modrm = getUChar(delta);
@@ -11622,7 +11622,7 @@
 }
 
 
-static Long dis_MOVMSKPS_256 ( VexAbiInfo* vbi, Prefix pfx, Long delta )
+static Long dis_MOVMSKPS_256 ( const VexAbiInfo* vbi, Prefix pfx, Long delta )
 {
    UChar modrm = getUChar(delta);
    UInt   rG   = gregOfRexRM(pfx,modrm);
@@ -11672,7 +11672,7 @@
 }
 
 
-static Long dis_MOVMSKPD_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MOVMSKPD_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    UChar modrm = getUChar(delta);
@@ -11694,7 +11694,7 @@
 }
 
 
-static Long dis_MOVMSKPD_256 ( VexAbiInfo* vbi, Prefix pfx, Long delta )
+static Long dis_MOVMSKPD_256 ( const VexAbiInfo* vbi, Prefix pfx, Long delta )
 {
    UChar modrm = getUChar(delta);
    UInt   rG   = gregOfRexRM(pfx,modrm);
@@ -11728,7 +11728,7 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F__SSE2 ( Bool* decode_OK,
-                        VexAbiInfo* vbi,
+                        const VexAbiInfo* vbi,
                         Prefix pfx, Int sz, Long deltaIN,
                         DisResult* dres )
 {
@@ -14631,7 +14631,7 @@
 /*---                                                      ---*/
 /*------------------------------------------------------------*/
 
-static Long dis_MOVDDUP_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MOVDDUP_128 ( const VexAbiInfo* vbi, Prefix pfx,
                               Long delta, Bool isAvx )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -14661,7 +14661,7 @@
 }
 
 
-static Long dis_MOVDDUP_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MOVDDUP_256 ( const VexAbiInfo* vbi, Prefix pfx,
                               Long delta )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -14693,7 +14693,7 @@
 }
 
 
-static Long dis_MOVSxDUP_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MOVSxDUP_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx, Bool isL )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -14727,7 +14727,7 @@
 }
 
 
-static Long dis_MOVSxDUP_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_MOVSxDUP_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isL )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -14807,7 +14807,7 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F__SSE3 ( Bool* decode_OK,
-                        VexAbiInfo* vbi,
+                        const VexAbiInfo* vbi,
                         Prefix pfx, Int sz, Long deltaIN )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -15097,7 +15097,7 @@
 }
 
 
-static Long dis_PHADD_128 ( VexAbiInfo* vbi, Prefix pfx, Long delta,
+static Long dis_PHADD_128 ( const VexAbiInfo* vbi, Prefix pfx, Long delta,
                             Bool isAvx, UChar opc )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -15171,7 +15171,8 @@
 }
 
 
-static Long dis_PHADD_256 ( VexAbiInfo* vbi, Prefix pfx, Long delta, UChar opc )
+static Long dis_PHADD_256 ( const VexAbiInfo* vbi, Prefix pfx, Long delta,
+                            UChar opc )
 {
    IRTemp addr   = IRTemp_INVALID;
    Int    alen   = 0;
@@ -15287,7 +15288,7 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F38__SupSSE3 ( Bool* decode_OK,
-                             VexAbiInfo* vbi,
+                             const VexAbiInfo* vbi,
                              Prefix pfx, Int sz, Long deltaIN )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -15806,7 +15807,7 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F3A__SupSSE3 ( Bool* decode_OK,
-                             VexAbiInfo* vbi,
+                             const VexAbiInfo* vbi,
                              Prefix pfx, Int sz, Long deltaIN )
 {
    Long   d64   = 0;
@@ -15932,8 +15933,8 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F__SSE4 ( Bool* decode_OK,
-                        VexArchInfo* archinfo,
-                        VexAbiInfo* vbi,
+                        const VexArchInfo* archinfo,
+                        const VexAbiInfo* vbi,
                         Prefix pfx, Int sz, Long deltaIN )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -16186,7 +16187,7 @@
    return res;
 }
 
-static Long dis_VBLENDV_128 ( VexAbiInfo* vbi, Prefix pfx, Long delta,
+static Long dis_VBLENDV_128 ( const VexAbiInfo* vbi, Prefix pfx, Long delta,
                               const HChar *name, UInt gran, IROp opSAR )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16225,7 +16226,7 @@
    return delta;
 }
 
-static Long dis_VBLENDV_256 ( VexAbiInfo* vbi, Prefix pfx, Long delta,
+static Long dis_VBLENDV_256 ( const VexAbiInfo* vbi, Prefix pfx, Long delta,
                               const HChar *name, UInt gran, IROp opSAR128 )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16364,7 +16365,7 @@
 
 /* Handles 128 bit versions of PTEST, VTESTPS or VTESTPD.
    sign is 0 for PTEST insn, 32 for VTESTPS and 64 for VTESTPD. */
-static Long dis_xTESTy_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_xTESTy_128 ( const VexAbiInfo* vbi, Prefix pfx,
                              Long delta, Bool isAvx, Int sign )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16417,7 +16418,7 @@
 
 /* Handles 256 bit versions of PTEST, VTESTPS or VTESTPD.
    sign is 0 for PTEST insn, 32 for VTESTPS and 64 for VTESTPD. */
-static Long dis_xTESTy_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_xTESTy_256 ( const VexAbiInfo* vbi, Prefix pfx,
                              Long delta, Int sign )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16475,7 +16476,7 @@
 
 
 /* Handles 128 bit versions of PMOVZXBW and PMOVSXBW. */
-static Long dis_PMOVxXBW_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXBW_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16518,7 +16519,7 @@
 
 
 /* Handles 256 bit versions of PMOVZXBW and PMOVSXBW. */
-static Long dis_PMOVxXBW_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXBW_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16558,7 +16559,7 @@
 }
 
 
-static Long dis_PMOVxXWD_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXWD_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16597,7 +16598,7 @@
 }
 
 
-static Long dis_PMOVxXWD_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXWD_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16636,7 +16637,7 @@
 }
 
 
-static Long dis_PMOVSXWQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVSXWQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -16669,7 +16670,7 @@
 }
 
 
-static Long dis_PMOVSXWQ_256 ( VexAbiInfo* vbi, Prefix pfx, Long delta )
+static Long dis_PMOVSXWQ_256 ( const VexAbiInfo* vbi, Prefix pfx, Long delta )
 {
    IRTemp addr     = IRTemp_INVALID;
    Int    alen     = 0;
@@ -16704,7 +16705,7 @@
 }
 
 
-static Long dis_PMOVZXWQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVZXWQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -16740,7 +16741,7 @@
 }
 
 
-static Long dis_PMOVZXWQ_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVZXWQ_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -16780,7 +16781,7 @@
 
 
 /* Handles 128 bit versions of PMOVZXDQ and PMOVSXDQ. */
-static Long dis_PMOVxXDQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXDQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16827,7 +16828,7 @@
 
 
 /* Handles 256 bit versions of PMOVZXDQ and PMOVSXDQ. */
-static Long dis_PMOVxXDQ_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXDQ_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16880,7 +16881,7 @@
 
 
 /* Handles 128 bit versions of PMOVZXBD and PMOVSXBD. */
-static Long dis_PMOVxXBD_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXBD_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16923,7 +16924,7 @@
 
 
 /* Handles 256 bit versions of PMOVZXBD and PMOVSXBD. */
-static Long dis_PMOVxXBD_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVxXBD_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool xIsZ )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -16970,7 +16971,7 @@
 
 
 /* Handles 128 bit versions of PMOVSXBQ. */
-static Long dis_PMOVSXBQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVSXBQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -17003,7 +17004,7 @@
 
 
 /* Handles 256 bit versions of PMOVSXBQ. */
-static Long dis_PMOVSXBQ_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVSXBQ_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -17049,7 +17050,7 @@
 
 
 /* Handles 128 bit versions of PMOVZXBQ. */
-static Long dis_PMOVZXBQ_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVZXBQ_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta, Bool isAvx )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -17088,7 +17089,7 @@
 
 
 /* Handles 256 bit versions of PMOVZXBQ. */
-static Long dis_PMOVZXBQ_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PMOVZXBQ_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -17132,7 +17133,7 @@
 }
 
 
-static Long dis_PHMINPOSUW_128 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PHMINPOSUW_128 ( const VexAbiInfo* vbi, Prefix pfx,
                                  Long delta, Bool isAvx )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -17172,7 +17173,7 @@
 }
 
 
-static Long dis_AESx ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_AESx ( const VexAbiInfo* vbi, Prefix pfx,
                        Long delta, Bool isAvx, UChar opc )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -17264,7 +17265,7 @@
    return delta;
 }
 
-static Long dis_AESKEYGENASSIST ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_AESKEYGENASSIST ( const VexAbiInfo* vbi, Prefix pfx,
                                   Long delta, Bool isAvx )
 {
    IRTemp addr   = IRTemp_INVALID;
@@ -17332,7 +17333,7 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F38__SSE4 ( Bool* decode_OK,
-                          VexAbiInfo* vbi,
+                          const VexAbiInfo* vbi,
                           Prefix pfx, Int sz, Long deltaIN )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -17858,7 +17859,7 @@
 /*---                                                      ---*/
 /*------------------------------------------------------------*/
 
-static Long dis_PEXTRW ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PEXTRW ( const VexAbiInfo* vbi, Prefix pfx,
                          Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -17913,7 +17914,7 @@
 }
 
 
-static Long dis_PEXTRD ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PEXTRD ( const VexAbiInfo* vbi, Prefix pfx,
                          Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -17966,7 +17967,7 @@
 }
 
 
-static Long dis_PEXTRQ ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PEXTRQ ( const VexAbiInfo* vbi, Prefix pfx,
                          Long delta, Bool isAvx )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -18147,7 +18148,7 @@
 
 /* This can fail, in which case it returns the original (unchanged)
    delta. */
-static Long dis_PCMPxSTRx ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PCMPxSTRx ( const VexAbiInfo* vbi, Prefix pfx,
                             Long delta, Bool isAvx, UChar opc )
 {
    Long   delta0  = delta;
@@ -18390,7 +18391,7 @@
 }
 
 
-static Long dis_PEXTRB_128_GtoE ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_PEXTRB_128_GtoE ( const VexAbiInfo* vbi, Prefix pfx,
                                   Long delta, Bool isAvx )
 {
    IRTemp addr     = IRTemp_INVALID;
@@ -18566,7 +18567,7 @@
    return res;
 }
 
-static Long dis_EXTRACTPS ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_EXTRACTPS ( const VexAbiInfo* vbi, Prefix pfx,
                             Long delta, Bool isAvx )
 {
    IRTemp addr       = IRTemp_INVALID;
@@ -18645,7 +18646,7 @@
 __attribute__((noinline))
 static
 Long dis_ESC_0F3A__SSE4 ( Bool* decode_OK,
-                          VexAbiInfo* vbi,
+                          const VexAbiInfo* vbi,
                           Prefix pfx, Int sz, Long deltaIN )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -19331,8 +19332,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -21042,8 +21043,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -22008,8 +22009,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -22093,8 +22094,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -22141,7 +22142,7 @@
 /* FIXME: common up with the _256_ version below? */
 static
 Long dis_VEX_NDS_128_AnySimdPfx_0F_WIG (
-        /*OUT*/Bool* uses_vvvv, VexAbiInfo* vbi,
+        /*OUT*/Bool* uses_vvvv, const VexAbiInfo* vbi,
         Prefix pfx, Long delta, const HChar* name,
         /* The actual operation.  Use either 'op' or 'opfn',
            but not both. */
@@ -22209,7 +22210,7 @@
    args. */
 static
 Long dis_VEX_NDS_128_AnySimdPfx_0F_WIG_simple (
-        /*OUT*/Bool* uses_vvvv, VexAbiInfo* vbi,
+        /*OUT*/Bool* uses_vvvv, const VexAbiInfo* vbi,
         Prefix pfx, Long delta, const HChar* name,
         IROp op
      )
@@ -22224,7 +22225,7 @@
    arg, and no swapping of args. */
 static
 Long dis_VEX_NDS_128_AnySimdPfx_0F_WIG_complex (
-        /*OUT*/Bool* uses_vvvv, VexAbiInfo* vbi,
+        /*OUT*/Bool* uses_vvvv, const VexAbiInfo* vbi,
         Prefix pfx, Long delta, const HChar* name,
         IRTemp(*opFn)(IRTemp,IRTemp)
      )
@@ -22237,7 +22238,7 @@
 
 /* Vector by scalar shift of V by the amount specified at the bottom
    of E. */
-static ULong dis_AVX128_shiftV_byE ( VexAbiInfo* vbi,
+static ULong dis_AVX128_shiftV_byE ( const VexAbiInfo* vbi,
                                      Prefix pfx, Long delta, 
                                      const HChar* opname, IROp op )
 {
@@ -22311,7 +22312,7 @@
 
 /* Vector by scalar shift of V by the amount specified at the bottom
    of E. */
-static ULong dis_AVX256_shiftV_byE ( VexAbiInfo* vbi,
+static ULong dis_AVX256_shiftV_byE ( const VexAbiInfo* vbi,
                                      Prefix pfx, Long delta, 
                                      const HChar* opname, IROp op )
 {
@@ -22387,7 +22388,7 @@
    of E.  Vector by vector shifts are defined for all shift amounts,
    so not using Iop_S*x* here (and SSE2 doesn't support variable shifts
    anyway).  */
-static ULong dis_AVX_var_shiftV_byE ( VexAbiInfo* vbi,
+static ULong dis_AVX_var_shiftV_byE ( const VexAbiInfo* vbi,
                                       Prefix pfx, Long delta,
                                       const HChar* opname, IROp op, Bool isYMM )
 {
@@ -22618,7 +22619,7 @@
    copies the upper half of the left operand to the result.
 */
 static Long dis_AVX128_E_V_to_G_lo64 ( /*OUT*/Bool* uses_vvvv,
-                                       VexAbiInfo* vbi,
+                                       const VexAbiInfo* vbi,
                                        Prefix pfx, Long delta, 
                                        const HChar* opname, IROp op )
 {
@@ -22661,7 +22662,7 @@
    copies the upper half of the operand to the result.
 */
 static Long dis_AVX128_E_V_to_G_lo64_unary ( /*OUT*/Bool* uses_vvvv,
-                                             VexAbiInfo* vbi,
+                                             const VexAbiInfo* vbi,
                                              Prefix pfx, Long delta, 
                                              const HChar* opname, IROp op )
 {
@@ -22708,7 +22709,7 @@
    copies the upper 3/4 of the operand to the result.
 */
 static Long dis_AVX128_E_V_to_G_lo32_unary ( /*OUT*/Bool* uses_vvvv,
-                                             VexAbiInfo* vbi,
+                                             const VexAbiInfo* vbi,
                                              Prefix pfx, Long delta, 
                                              const HChar* opname, IROp op )
 {
@@ -22755,7 +22756,7 @@
    copies the upper 3/4 of the left operand to the result.
 */
 static Long dis_AVX128_E_V_to_G_lo32 ( /*OUT*/Bool* uses_vvvv,
-                                       VexAbiInfo* vbi,
+                                       const VexAbiInfo* vbi,
                                        Prefix pfx, Long delta, 
                                        const HChar* opname, IROp op )
 {
@@ -22795,7 +22796,7 @@
    G[255:128] = 0.
 */
 static Long dis_AVX128_E_V_to_G ( /*OUT*/Bool* uses_vvvv,
-                                  VexAbiInfo* vbi,
+                                  const VexAbiInfo* vbi,
                                   Prefix pfx, Long delta, 
                                   const HChar* opname, IROp op )
 {
@@ -22811,7 +22812,7 @@
    original delta to indicate failure. */
 static
 Long dis_AVX128_cmp_V_E_to_G ( /*OUT*/Bool* uses_vvvv,
-                               VexAbiInfo* vbi,
+                               const VexAbiInfo* vbi,
                                Prefix pfx, Long delta, 
                                const HChar* opname, Bool all_lanes, Int sz )
 {
@@ -22921,7 +22922,7 @@
    original delta to indicate failure. */
 static
 Long dis_AVX256_cmp_V_E_to_G ( /*OUT*/Bool* uses_vvvv,
-                               VexAbiInfo* vbi,
+                               const VexAbiInfo* vbi,
                                Prefix pfx, Long delta, 
                                const HChar* opname, Int sz )
 {
@@ -22991,7 +22992,7 @@
 /* Handles AVX128 unary E-to-G all-lanes operations. */
 static
 Long dis_AVX128_E_to_G_unary ( /*OUT*/Bool* uses_vvvv,
-                               VexAbiInfo* vbi,
+                               const VexAbiInfo* vbi,
                                Prefix pfx, Long delta, 
                                const HChar* opname,
                                IRTemp (*opFn)(IRTemp) )
@@ -23024,7 +23025,7 @@
 /* Handles AVX128 unary E-to-G all-lanes operations. */
 static
 Long dis_AVX128_E_to_G_unary_all ( /*OUT*/Bool* uses_vvvv,
-                                   VexAbiInfo* vbi,
+                                   const VexAbiInfo* vbi,
                                    Prefix pfx, Long delta, 
                                    const HChar* opname, IROp op )
 {
@@ -23054,7 +23055,7 @@
 /* FIXME: common up with the _128_ version above? */
 static
 Long dis_VEX_NDS_256_AnySimdPfx_0F_WIG (
-        /*OUT*/Bool* uses_vvvv, VexAbiInfo* vbi,
+        /*OUT*/Bool* uses_vvvv, const VexAbiInfo* vbi,
         Prefix pfx, Long delta, const HChar* name,
         /* The actual operation.  Use either 'op' or 'opfn',
            but not both. */
@@ -23121,7 +23122,7 @@
    G[255:0] = V[255:0] `op` E[255:0]
 */
 static Long dis_AVX256_E_V_to_G ( /*OUT*/Bool* uses_vvvv,
-                                  VexAbiInfo* vbi,
+                                  const VexAbiInfo* vbi,
                                   Prefix pfx, Long delta, 
                                   const HChar* opname, IROp op )
 {
@@ -23137,7 +23138,7 @@
    args. */
 static
 Long dis_VEX_NDS_256_AnySimdPfx_0F_WIG_simple (
-        /*OUT*/Bool* uses_vvvv, VexAbiInfo* vbi,
+        /*OUT*/Bool* uses_vvvv, const VexAbiInfo* vbi,
         Prefix pfx, Long delta, const HChar* name,
         IROp op
      )
@@ -23152,7 +23153,7 @@
    arg, and no swapping of args. */
 static
 Long dis_VEX_NDS_256_AnySimdPfx_0F_WIG_complex (
-        /*OUT*/Bool* uses_vvvv, VexAbiInfo* vbi,
+        /*OUT*/Bool* uses_vvvv, const VexAbiInfo* vbi,
         Prefix pfx, Long delta, const HChar* name,
         IRTemp(*opFn)(IRTemp,IRTemp)
      )
@@ -23166,7 +23167,7 @@
 /* Handles AVX256 unary E-to-G all-lanes operations. */
 static
 Long dis_AVX256_E_to_G_unary ( /*OUT*/Bool* uses_vvvv,
-                               VexAbiInfo* vbi,
+                               const VexAbiInfo* vbi,
                                Prefix pfx, Long delta,
                                const HChar* opname,
                                IRTemp (*opFn)(IRTemp) )
@@ -23199,7 +23200,7 @@
 /* Handles AVX256 unary E-to-G all-lanes operations. */
 static
 Long dis_AVX256_E_to_G_unary_all ( /*OUT*/Bool* uses_vvvv,
-                                   VexAbiInfo* vbi,
+                                   const VexAbiInfo* vbi,
                                    Prefix pfx, Long delta, 
                                    const HChar* opname, IROp op )
 {
@@ -23228,7 +23229,7 @@
 
 /* The use of ReinterpF64asI64 is ugly.  Surely could do better if we
    had a variant of Iop_64x4toV256 that took F64s as args instead. */
-static Long dis_CVTDQ2PD_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTDQ2PD_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -23264,7 +23265,7 @@
 }
 
 
-static Long dis_CVTPD2PS_256 ( VexAbiInfo* vbi, Prefix pfx,
+static Long dis_CVTPD2PS_256 ( const VexAbiInfo* vbi, Prefix pfx,
                                Long delta )
 {
    IRTemp addr  = IRTemp_INVALID;
@@ -23396,8 +23397,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -27012,7 +27013,7 @@
 }
 
 static Long dis_SHIFTX ( /*OUT*/Bool* uses_vvvv,
-                         VexAbiInfo* vbi, Prefix pfx, Long delta,
+                         const VexAbiInfo* vbi, Prefix pfx, Long delta,
                          const HChar* opname, IROp op8 )
 {
    HChar   dis_buf[50];
@@ -27047,7 +27048,7 @@
 }
 
 
-static Long dis_FMA ( VexAbiInfo* vbi, Prefix pfx, Long delta, UChar opc )
+static Long dis_FMA ( const VexAbiInfo* vbi, Prefix pfx, Long delta, UChar opc )
 {
    UChar  modrm   = getUChar(delta);
    UInt   rG      = gregOfRexRM(pfx, modrm);
@@ -27235,7 +27236,7 @@
 
 
 /* Masked load.  */
-static ULong dis_VMASKMOV_load ( Bool *uses_vvvv, VexAbiInfo* vbi,
+static ULong dis_VMASKMOV_load ( Bool *uses_vvvv, const VexAbiInfo* vbi,
                                  Prefix pfx, Long delta,
                                  const HChar* opname, Bool isYMM, IRType ty )
 {
@@ -27296,7 +27297,7 @@
 
 
 /* Gather.  */
-static ULong dis_VGATHER ( Bool *uses_vvvv, VexAbiInfo* vbi,
+static ULong dis_VGATHER ( Bool *uses_vvvv, const VexAbiInfo* vbi,
                            Prefix pfx, Long delta,
                            const HChar* opname, Bool isYMM,
                            Bool isVM64x, IRType ty )
@@ -27398,8 +27399,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -29559,8 +29560,8 @@
         Bool         (*resteerOkFn) ( /*opaque*/void*, Addr64 ),
         Bool         resteerCisOk,
         void*        callback_opaque,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  vbi,
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  vbi,
         Prefix pfx, Int sz, Long deltaIN 
      )
 {
@@ -31147,8 +31148,8 @@
              Bool         resteerCisOk,
              void*        callback_opaque,
              Long         delta64,
-             VexArchInfo* archinfo,
-             VexAbiInfo*  vbi,
+             const VexArchInfo* archinfo,
+             const VexAbiInfo*  vbi,
              Bool         sigill_diag
           )
 {
@@ -31785,8 +31786,8 @@
                            Long         delta,
                            Addr64       guest_IP,
                            VexArch      guest_arch,
-                           VexArchInfo* archinfo,
-                           VexAbiInfo*  abiinfo,
+                           const VexArchInfo* archinfo,
+                           const VexAbiInfo*  abiinfo,
                            VexEndness   host_endness_IN,
                            Bool         sigill_diag_IN )
 {
diff --git a/priv/guest_arm64_defs.h b/priv/guest_arm64_defs.h
index 5656786..3014bac 100644
--- a/priv/guest_arm64_defs.h
+++ b/priv/guest_arm64_defs.h
@@ -48,8 +48,8 @@
                            Long         delta,
                            Addr64       guest_IP,
                            VexArch      guest_arch,
-                           VexArchInfo* archinfo,
-                           VexAbiInfo*  abiinfo,
+                           const VexArchInfo* archinfo,
+                           const VexAbiInfo*  abiinfo,
                            VexEndness   host_endness,
                            Bool         sigill_diag );
 
diff --git a/priv/guest_arm64_toIR.c b/priv/guest_arm64_toIR.c
index c8fadd9..b8751ea 100644
--- a/priv/guest_arm64_toIR.c
+++ b/priv/guest_arm64_toIR.c
@@ -6415,7 +6415,7 @@
 
 static
 Bool dis_ARM64_branch_etc(/*MB_OUT*/DisResult* dres, UInt insn,
-                          VexArchInfo* archinfo)
+                          const VexArchInfo* archinfo)
 {
 #  define INSN(_bMax,_bMin)  SLICE_UInt(insn, (_bMax), (_bMin))
 
@@ -12791,8 +12791,8 @@
         Bool         resteerCisOk,
         void*        callback_opaque,
         const UChar* guest_instr,
-        VexArchInfo* archinfo,
-        VexAbiInfo*  abiinfo
+        const VexArchInfo* archinfo,
+        const VexAbiInfo*  abiinfo
      )
 {
    // A macro to fish bits out of 'insn'.
@@ -12973,8 +12973,8 @@
                            Long         delta_IN,
                            Addr64       guest_IP,
                            VexArch      guest_arch,
-                           VexArchInfo* archinfo,
-                           VexAbiInfo*  abiinfo,
+                           const VexArchInfo* archinfo,
+                           const VexAbiInfo*  abiinfo,
                            VexEndness   host_endness_IN,
                            Bool         sigill_diag_IN )
 {
diff --git a/priv/guest_arm_defs.h b/priv/guest_arm_defs.h
index a931644..b91af1d 100644
--- a/priv/guest_arm_defs.h
+++ b/priv/guest_arm_defs.h
@@ -50,8 +50,8 @@
                          Long         delta,
                          Addr64       guest_IP,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness,
                          Bool         sigill_diag );
 
diff --git a/priv/guest_arm_toIR.c b/priv/guest_arm_toIR.c
index dbead8f..5c63619 100644
--- a/priv/guest_arm_toIR.c
+++ b/priv/guest_arm_toIR.c
@@ -14435,7 +14435,7 @@
    here, since they are all in NV space.
 */
 static Bool decode_NV_instruction ( /*MOD*/DisResult* dres,
-                                    VexArchInfo* archinfo,
+                                    const VexArchInfo* archinfo,
                                     UInt insn )
 {
 #  define INSN(_bMax,_bMin)  SLICE_UInt(insn, (_bMax), (_bMin))
@@ -14591,8 +14591,8 @@
              Bool         resteerCisOk,
              void*        callback_opaque,
              const UChar* guest_instr,
-             VexArchInfo* archinfo,
-             VexAbiInfo*  abiinfo,
+             const VexArchInfo* archinfo,
+             const VexAbiInfo*  abiinfo,
              Bool         sigill_diag
           )
 {
@@ -17423,8 +17423,8 @@
              Bool         resteerCisOk,
              void*        callback_opaque,
              const UChar* guest_instr,
-             VexArchInfo* archinfo,
-             VexAbiInfo*  abiinfo,
+             const VexArchInfo* archinfo,
+             const VexAbiInfo*  abiinfo,
              Bool         sigill_diag
           )
 {
@@ -22022,8 +22022,8 @@
                          Long         delta_ENCODED,
                          Addr64       guest_IP_ENCODED,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness_IN,
                          Bool         sigill_diag_IN )
 {
diff --git a/priv/guest_generic_bb_to_IR.c b/priv/guest_generic_bb_to_IR.c
index 3868120..d3c0ede 100644
--- a/priv/guest_generic_bb_to_IR.c
+++ b/priv/guest_generic_bb_to_IR.c
@@ -189,8 +189,8 @@
          /*IN*/ VexEndness       host_endness,
          /*IN*/ Bool             sigill_diag,
          /*IN*/ VexArch          arch_guest,
-         /*IN*/ VexArchInfo*     archinfo_guest,
-         /*IN*/ VexAbiInfo*      abiinfo_both,
+         /*IN*/ const VexArchInfo* archinfo_guest,
+         /*IN*/ const VexAbiInfo*  abiinfo_both,
          /*IN*/ IRType           guest_word_type,
          /*IN*/ UInt             (*needs_self_check)(void*,const VexGuestExtents*),
          /*IN*/ Bool             (*preamble_function)(void*,IRSB*),
@@ -527,9 +527,8 @@
       UInt     host_word_szB = sizeof(HWord);
       IRType   host_word_type = Ity_INVALID;
 
-      VexGuestExtents vge_tmp = *vge;
       UInt extents_needing_check
-         = needs_self_check(callback_opaque, &vge_tmp);
+         = needs_self_check(callback_opaque, vge);
 
       if (host_word_szB == 4) host_word_type = Ity_I32;
       if (host_word_szB == 8) host_word_type = Ity_I64;
diff --git a/priv/guest_generic_bb_to_IR.h b/priv/guest_generic_bb_to_IR.h
index f0b9f76..93ad0f1 100644
--- a/priv/guest_generic_bb_to_IR.h
+++ b/priv/guest_generic_bb_to_IR.h
@@ -147,10 +147,10 @@
 
       /* Info about the guest architecture */
       /*IN*/  VexArch      guest_arch,
-      /*IN*/  VexArchInfo* archinfo,
+      /*IN*/  const VexArchInfo* archinfo,
 
       /* ABI info for both guest and host */
-      /*IN*/  VexAbiInfo*  abiinfo,
+      /*IN*/  const VexAbiInfo*  abiinfo,
 
       /* The endianness of the host */
       /*IN*/  VexEndness   host_endness,
@@ -179,8 +179,8 @@
          /*IN*/ VexEndness       host_endness,
          /*IN*/ Bool             sigill_diag,
          /*IN*/ VexArch          arch_guest,
-         /*IN*/ VexArchInfo*     archinfo_guest,
-         /*IN*/ VexAbiInfo*      abiinfo_both,
+         /*IN*/ const VexArchInfo* archinfo_guest,
+         /*IN*/ const VexAbiInfo*  abiinfo_both,
          /*IN*/ IRType           guest_word_type,
          /*IN*/ UInt             (*needs_self_check)(void*,const VexGuestExtents*),
          /*IN*/ Bool             (*preamble_function)(void*,IRSB*),
diff --git a/priv/guest_mips_defs.h b/priv/guest_mips_defs.h
index c540c15..3a1ee94 100644
--- a/priv/guest_mips_defs.h
+++ b/priv/guest_mips_defs.h
@@ -49,8 +49,8 @@
                                  Long         delta,
                                  Addr64       guest_IP,
                                  VexArch      guest_arch,
-                                 VexArchInfo* archinfo,
-                                 VexAbiInfo*  abiinfo,
+                                 const VexArchInfo* archinfo,
+                                 const VexAbiInfo*  abiinfo,
                                  VexEndness   host_endness,
                                  Bool         sigill_diag );
 
diff --git a/priv/guest_mips_toIR.c b/priv/guest_mips_toIR.c
index a41ce41..e40b717 100644
--- a/priv/guest_mips_toIR.c
+++ b/priv/guest_mips_toIR.c
@@ -12012,8 +12012,8 @@
                                      Bool         resteerCisOk,
                                      void*        callback_opaque,
                                      Long         delta64,
-                                     VexArchInfo* archinfo,
-                                     VexAbiInfo*  abiinfo,
+                                     const VexArchInfo* archinfo,
+                                     const VexAbiInfo*  abiinfo,
                                      Bool         sigill_diag )
 {
    IRTemp t0, t1 = 0, t2, t3, t4, t5, t6, t7;
@@ -17289,8 +17289,8 @@
                          Long         delta,
                          Addr64       guest_IP,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness_IN,
                          Bool         sigill_diag_IN )
 {
diff --git a/priv/guest_ppc_defs.h b/priv/guest_ppc_defs.h
index 25d9fe3..b8798cf 100644
--- a/priv/guest_ppc_defs.h
+++ b/priv/guest_ppc_defs.h
@@ -59,8 +59,8 @@
                          Long         delta,
                          Addr64       guest_IP,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness,
                          Bool         sigill_diag );
 
diff --git a/priv/guest_ppc_toIR.c b/priv/guest_ppc_toIR.c
index e49ac96..f4d0af3 100644
--- a/priv/guest_ppc_toIR.c
+++ b/priv/guest_ppc_toIR.c
@@ -1,5 +1,4 @@
 
-
 /*--------------------------------------------------------------------*/
 /*--- begin                                       guest_ppc_toIR.c ---*/
 /*--------------------------------------------------------------------*/
@@ -226,7 +225,7 @@
 // most platforms it's the identity function.  Unfortunately, on
 // ppc64-linux it isn't (sigh) and ditto for ppc32-aix5 and
 // ppc64-aix5.
-static void* fnptr_to_fnentry( VexAbiInfo* vbi, void* f )
+static void* fnptr_to_fnentry( const VexAbiInfo* vbi, void* f )
 {
    if (vbi->host_ppc_calls_use_fndescrs) {
       /* f is a pointer to a 3-word function descriptor, of which the
@@ -1764,7 +1763,7 @@
    ppc32 doesn't have this "feature" (how fortunate for it).  nia is
    the address of the next instruction to be executed.
 */
-static void make_redzone_AbiHint ( VexAbiInfo* vbi, 
+static void make_redzone_AbiHint ( const VexAbiInfo* vbi, 
                                    IRTemp nia, const HChar* who )
 {
    Int szB = vbi->guest_stack_redzone_size;
@@ -5156,7 +5155,7 @@
 /*
   Integer Store Instructions
 */
-static Bool dis_int_store ( UInt theInstr, VexAbiInfo* vbi )
+static Bool dis_int_store ( UInt theInstr, const VexAbiInfo* vbi )
 {
    /* D-Form, X-Form, DS-Form */
    UChar opc1    = ifieldOPC(theInstr);
@@ -5685,7 +5684,7 @@
   Integer Branch Instructions
 */
 static Bool dis_branch ( UInt theInstr, 
-                         VexAbiInfo* vbi,
+                         const VexAbiInfo* vbi,
                          /*OUT*/DisResult* dres,
                          Bool (*resteerOkFn)(void*,Addr64),
                          void* callback_opaque )
@@ -6191,7 +6190,7 @@
   System Linkage Instructions
 */
 static Bool dis_syslink ( UInt theInstr, 
-                          VexAbiInfo* abiinfo, DisResult* dres )
+                          const VexAbiInfo* abiinfo, DisResult* dres )
 {
    IRType ty = mode64 ? Ity_I64 : Ity_I32;
 
@@ -6879,7 +6878,7 @@
 /*
   Processor Control Instructions
 */
-static Bool dis_proc_ctl ( VexAbiInfo* vbi, UInt theInstr )
+static Bool dis_proc_ctl ( const VexAbiInfo* vbi, UInt theInstr )
 {
    UChar opc1     = ifieldOPC(theInstr);
    
@@ -7282,7 +7281,7 @@
 */
 static Bool dis_cache_manage ( UInt         theInstr, 
                                DisResult*   dres,
-                               VexArchInfo* guest_archinfo )
+                               const VexArchInfo* guest_archinfo )
 {
    /* X-Form */
    UChar opc1    = ifieldOPC(theInstr);
@@ -15580,7 +15579,7 @@
 /*
   AltiVec Load Instructions
 */
-static Bool dis_av_load ( VexAbiInfo* vbi, UInt theInstr )
+static Bool dis_av_load ( const VexAbiInfo* vbi, UInt theInstr )
 {
    /* X-Form */
    UChar opc1     = ifieldOPC(theInstr);
@@ -18297,7 +18296,7 @@
 }
 
 static Bool dis_transactional_memory ( UInt theInstr, UInt nextInstr,
-                                       VexAbiInfo* vbi,
+                                       const VexAbiInfo* vbi,
                                        /*OUT*/DisResult* dres,
                                        Bool (*resteerOkFn)(void*,Addr64),
                                        void* callback_opaque )
@@ -18706,8 +18705,8 @@
              Bool         resteerCisOk,
              void*        callback_opaque,
              Long         delta64,
-             VexArchInfo* archinfo,
-             VexAbiInfo*  abiinfo,
+             const VexArchInfo* archinfo,
+             const VexAbiInfo*  abiinfo,
              Bool         sigill_diag
           )
 {
@@ -20190,8 +20189,8 @@
                          Long         delta,
                          Addr64       guest_IP,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness_IN,
                          Bool         sigill_diag_IN )
 {
diff --git a/priv/guest_s390_defs.h b/priv/guest_s390_defs.h
index 97c2a02..3baecec 100644
--- a/priv/guest_s390_defs.h
+++ b/priv/guest_s390_defs.h
@@ -48,8 +48,8 @@
                           Long         delta,
                           Addr64       guest_IP,
                           VexArch      guest_arch,
-                          VexArchInfo* archinfo,
-                          VexAbiInfo*  abiinfo,
+                          const VexArchInfo* archinfo,
+                          const VexAbiInfo*  abiinfo,
                           VexEndness   host_endness,
                           Bool         sigill_diag );
 
diff --git a/priv/guest_s390_toIR.c b/priv/guest_s390_toIR.c
index 2463a06..3c985ef 100644
--- a/priv/guest_s390_toIR.c
+++ b/priv/guest_s390_toIR.c
@@ -16665,8 +16665,8 @@
               Long         delta,
               Addr64       guest_IP,
               VexArch      guest_arch,
-              VexArchInfo *archinfo,
-              VexAbiInfo  *abiinfo,
+              const VexArchInfo *archinfo,
+              const VexAbiInfo  *abiinfo,
               VexEndness   host_endness,
               Bool         sigill_diag_IN)
 {
diff --git a/priv/guest_x86_defs.h b/priv/guest_x86_defs.h
index dd03056..e3c2ecc 100644
--- a/priv/guest_x86_defs.h
+++ b/priv/guest_x86_defs.h
@@ -58,8 +58,8 @@
                          Long         delta,
                          Addr64       guest_IP,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness,
                          Bool         sigill_diag );
 
diff --git a/priv/guest_x86_toIR.c b/priv/guest_x86_toIR.c
index be63fc4..12a96c9 100644
--- a/priv/guest_x86_toIR.c
+++ b/priv/guest_x86_toIR.c
@@ -6310,7 +6310,7 @@
 
 
 static
-UInt dis_bt_G_E ( VexAbiInfo* vbi,
+UInt dis_bt_G_E ( const VexAbiInfo* vbi,
                   UChar sorb, Bool locked, Int sz, Int delta, BtOp op )
 {
    HChar  dis_buf[50];
@@ -8065,8 +8065,8 @@
              Bool         resteerCisOk,
              void*        callback_opaque,
              Long         delta64,
-             VexArchInfo* archinfo,
-             VexAbiInfo*  vbi,
+             const VexArchInfo* archinfo,
+             const VexAbiInfo*  vbi,
              Bool         sigill_diag
           )
 {
@@ -15415,8 +15415,8 @@
                          Long         delta,
                          Addr64       guest_IP,
                          VexArch      guest_arch,
-                         VexArchInfo* archinfo,
-                         VexAbiInfo*  abiinfo,
+                         const VexArchInfo* archinfo,
+                         const VexAbiInfo*  abiinfo,
                          VexEndness   host_endness_IN,
                          Bool         sigill_diag_IN )
 {
diff --git a/priv/host_amd64_defs.h b/priv/host_amd64_defs.h
index 091ba80..89332c6 100644
--- a/priv/host_amd64_defs.h
+++ b/priv/host_amd64_defs.h
@@ -769,7 +769,7 @@
                               HReg rreg, Int offset, Bool );
 
 extern void         getAllocableRegs_AMD64 ( Int*, HReg** );
-extern HInstrArray* iselSB_AMD64           ( IRSB*, 
+extern HInstrArray* iselSB_AMD64           ( const IRSB*, 
                                              VexArch,
                                              const VexArchInfo*,
                                              const VexAbiInfo*,
diff --git a/priv/host_amd64_isel.c b/priv/host_amd64_isel.c
index e67ecba..4ccea9f 100644
--- a/priv/host_amd64_isel.c
+++ b/priv/host_amd64_isel.c
@@ -4850,7 +4850,7 @@
 
 /* Translate an entire SB to amd64 code. */
 
-HInstrArray* iselSB_AMD64 ( IRSB* bb,
+HInstrArray* iselSB_AMD64 ( const IRSB* bb,
                             VexArch      arch_host,
                             const VexArchInfo* archinfo_host,
                             const VexAbiInfo*  vbi/*UNUSED*/,
diff --git a/priv/host_arm64_defs.h b/priv/host_arm64_defs.h
index cda161b..319fde5 100644
--- a/priv/host_arm64_defs.h
+++ b/priv/host_arm64_defs.h
@@ -949,7 +949,7 @@
                               HReg rreg, Int offset, Bool );
 
 extern void getAllocableRegs_ARM64 ( Int*, HReg** );
-extern HInstrArray* iselSB_ARM64 ( IRSB*, 
+extern HInstrArray* iselSB_ARM64 ( const IRSB*, 
                                    VexArch,
                                    const VexArchInfo*,
                                    const VexAbiInfo*,
diff --git a/priv/host_arm64_isel.c b/priv/host_arm64_isel.c
index 5759994..06ba672 100644
--- a/priv/host_arm64_isel.c
+++ b/priv/host_arm64_isel.c
@@ -3864,7 +3864,7 @@
 
 /* Translate an entire SB to arm64 code. */
 
-HInstrArray* iselSB_ARM64 ( IRSB* bb,
+HInstrArray* iselSB_ARM64 ( const IRSB* bb,
                             VexArch      arch_host,
                             const VexArchInfo* archinfo_host,
                             const VexAbiInfo*  vbi/*UNUSED*/,
diff --git a/priv/host_arm_defs.h b/priv/host_arm_defs.h
index 65601e6..6d1a016 100644
--- a/priv/host_arm_defs.h
+++ b/priv/host_arm_defs.h
@@ -1039,7 +1039,7 @@
                             HReg rreg, Int offset, Bool );
 
 extern void getAllocableRegs_ARM ( Int*, HReg** );
-extern HInstrArray* iselSB_ARM   ( IRSB*, 
+extern HInstrArray* iselSB_ARM   ( const IRSB*, 
                                    VexArch,
                                    const VexArchInfo*,
                                    const VexAbiInfo*,
diff --git a/priv/host_arm_isel.c b/priv/host_arm_isel.c
index 753ec4a..1a3ff07 100644
--- a/priv/host_arm_isel.c
+++ b/priv/host_arm_isel.c
@@ -6312,7 +6312,7 @@
 
 /* Translate an entire SB to arm code. */
 
-HInstrArray* iselSB_ARM ( IRSB* bb,
+HInstrArray* iselSB_ARM ( const IRSB* bb,
                           VexArch      arch_host,
                           const VexArchInfo* archinfo_host,
                           const VexAbiInfo*  vbi/*UNUSED*/,
diff --git a/priv/host_mips_defs.h b/priv/host_mips_defs.h
index 8e2d0dc..9d67dee 100644
--- a/priv/host_mips_defs.h
+++ b/priv/host_mips_defs.h
@@ -727,7 +727,7 @@
                             HReg rreg, Int offset, Bool);
 
 extern void        getAllocableRegs_MIPS (Int *, HReg **, Bool mode64);
-extern HInstrArray *iselSB_MIPS          ( IRSB*,
+extern HInstrArray *iselSB_MIPS          ( const IRSB*,
                                            VexArch,
                                            const VexArchInfo*,
                                            const VexAbiInfo*,
diff --git a/priv/host_mips_isel.c b/priv/host_mips_isel.c
index c3bbd9a..ac8e6f9 100644
--- a/priv/host_mips_isel.c
+++ b/priv/host_mips_isel.c
@@ -4152,7 +4152,7 @@
 /*---------------------------------------------------------*/
 
 /* Translate an entire BB to mips code. */
-HInstrArray *iselSB_MIPS ( IRSB* bb,
+HInstrArray *iselSB_MIPS ( const IRSB* bb,
                            VexArch arch_host,
                            const VexArchInfo* archinfo_host,
                            const VexAbiInfo* vbi,
diff --git a/priv/host_ppc_defs.h b/priv/host_ppc_defs.h
index b5b7bf7..565534f 100644
--- a/priv/host_ppc_defs.h
+++ b/priv/host_ppc_defs.h
@@ -1157,7 +1157,7 @@
                             HReg rreg, Int offsetB, Bool mode64 );
 
 extern void         getAllocableRegs_PPC ( Int*, HReg**, Bool mode64 );
-extern HInstrArray* iselSB_PPC           ( IRSB*, 
+extern HInstrArray* iselSB_PPC           ( const IRSB*,
                                            VexArch,
                                            const VexArchInfo*,
                                            const VexAbiInfo*,
diff --git a/priv/host_ppc_isel.c b/priv/host_ppc_isel.c
index 7489b61..3c99a5b 100644
--- a/priv/host_ppc_isel.c
+++ b/priv/host_ppc_isel.c
@@ -6093,7 +6093,7 @@
 /*---------------------------------------------------------*/
 
 /* Translate an entire SB to ppc code. */
-HInstrArray* iselSB_PPC ( IRSB* bb, 
+HInstrArray* iselSB_PPC ( const IRSB* bb,
                           VexArch      arch_host,
                           const VexArchInfo* archinfo_host,
                           const VexAbiInfo*  vbi,
diff --git a/priv/host_s390_defs.c b/priv/host_s390_defs.c
index c2dd07b..c17335a 100644
--- a/priv/host_s390_defs.c
+++ b/priv/host_s390_defs.c
@@ -399,7 +399,7 @@
 
 
 void
-ppS390AMode(s390_amode *am)
+ppS390AMode(const s390_amode *am)
 {
    vex_printf("%s", s390_amode_as_string(am));
 }
diff --git a/priv/host_s390_defs.h b/priv/host_s390_defs.h
index 23c0c76..f5385ca 100644
--- a/priv/host_s390_defs.h
+++ b/priv/host_s390_defs.h
@@ -726,7 +726,7 @@
 /* --- Interface exposed to VEX                       --- */
 /*--------------------------------------------------------*/
 
-void ppS390AMode(s390_amode *);
+void ppS390AMode(const s390_amode *);
 void ppS390Instr(const s390_insn *, Bool mode64);
 void ppHRegS390(HReg);
 
@@ -741,7 +741,7 @@
 void  getAllocableRegs_S390( Int *, HReg **, Bool );
 void  genSpill_S390        ( HInstr **, HInstr **, HReg , Int , Bool );
 void  genReload_S390       ( HInstr **, HInstr **, HReg , Int , Bool );
-HInstrArray *iselSB_S390   ( IRSB *, VexArch, const VexArchInfo *,
+HInstrArray *iselSB_S390   ( const IRSB *, VexArch, const VexArchInfo *,
                              const VexAbiInfo *, Int, Int, Bool, Bool, Addr64);
 
 /* Return the number of bytes of code needed for an event check */
diff --git a/priv/host_s390_isel.c b/priv/host_s390_isel.c
index 3e8c3c6..9990ab1 100644
--- a/priv/host_s390_isel.c
+++ b/priv/host_s390_isel.c
@@ -4048,7 +4048,7 @@
    Do not assign it to a global variable! */
 
 HInstrArray *
-iselSB_S390(IRSB *bb, VexArch arch_host, const VexArchInfo *archinfo_host,
+iselSB_S390(const IRSB *bb, VexArch arch_host, const VexArchInfo *archinfo_host,
             const VexAbiInfo *vbi, Int offset_host_evcheck_counter,
             Int offset_host_evcheck_fail_addr, Bool chaining_allowed,
             Bool add_profinc, Addr64 max_ga)
diff --git a/priv/host_x86_defs.h b/priv/host_x86_defs.h
index c590d12..c679bbe 100644
--- a/priv/host_x86_defs.h
+++ b/priv/host_x86_defs.h
@@ -731,7 +731,7 @@
 extern X86Instr*    directReload_X86     ( X86Instr* i, 
                                            HReg vreg, Short spill_off );
 extern void         getAllocableRegs_X86 ( Int*, HReg** );
-extern HInstrArray* iselSB_X86           ( IRSB*, 
+extern HInstrArray* iselSB_X86           ( const IRSB*,
                                            VexArch,
                                            const VexArchInfo*,
                                            const VexAbiInfo*,
diff --git a/priv/host_x86_isel.c b/priv/host_x86_isel.c
index 97576df..900afd1 100644
--- a/priv/host_x86_isel.c
+++ b/priv/host_x86_isel.c
@@ -4409,7 +4409,7 @@
 
 /* Translate an entire SB to x86 code. */
 
-HInstrArray* iselSB_X86 ( IRSB* bb,
+HInstrArray* iselSB_X86 ( const IRSB* bb,
                           VexArch      arch_host,
                           const VexArchInfo* archinfo_host,
                           const VexAbiInfo*  vbi/*UNUSED*/,
diff --git a/priv/main_main.c b/priv/main_main.c
index 0d77e17..c48ea4d 100644
--- a/priv/main_main.c
+++ b/priv/main_main.c
@@ -219,7 +219,7 @@
    HInstr*      (*directReload) ( HInstr*, HReg, Short );
    void         (*ppInstr)      ( const HInstr*, Bool );
    void         (*ppReg)        ( HReg );
-   HInstrArray* (*iselSB)       ( IRSB*, VexArch, const VexArchInfo*,
+   HInstrArray* (*iselSB)       ( const IRSB*, VexArch, const VexArchInfo*,
                                   const VexAbiInfo*, Int, Int, Bool, Bool,
                                   Addr64 );
    Int          (*emit)         ( /*MB_MOD*/Bool*,