commit 3e2cb21e53cf9d5a3ef984ef5abbfd9683e516a8
author Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Thu Aug 27 14:35:23 2020 -0400
committer Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com> Mon Aug 31 07:46:31 2020 -0400
tree 2c867841b99692f73e5f43062004712658f51086
parent fd41dece39c7d6110951e0fd6fc1693663e7c10d

pan/mdg: Implement i/umul_high

As imul with a .hi modifier, which implies a 64-bit computation.

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6516>

src/panfrost/midgard/midgard_compile.c

diff --git a/src/panfrost/midgard/midgard_compile.c b/src/panfrost/midgard/midgard_compile.c
index 7ab8cd4..1b9ea1b 100644
--- a/src/panfrost/midgard/midgard_compile.c
+++ b/src/panfrost/midgard/midgard_compile.c
@@ -881,6 +881,8 @@
                 ALU_CASE(iadd, iadd);
                 ALU_CASE(isub, isub);
                 ALU_CASE(imul, imul);
+                ALU_CASE(imul_high, imul);
+                ALU_CASE(umul_high, imul);
 
                 /* Zero shoved as second-arg */
                 ALU_CASE(iabs, iabsdiff);
@@ -1059,7 +1061,9 @@
         unsigned outmod = 0;
         bool is_int = midgard_is_integer_op(op);
 
-        if (midgard_is_integer_out_op(op)) {
+        if (instr->op == nir_op_umul_high || instr->op == nir_op_imul_high) {
+                outmod = midgard_outmod_int_high;
+        } else if (midgard_is_integer_out_op(op)) {
                 outmod = midgard_outmod_int_wrap;
         } else if (instr->op == nir_op_fsat) {
                 outmod = midgard_outmod_sat;
@@ -2392,6 +2396,13 @@
                 break;
         }
 
+        /* High implies computing at a higher bitsize, e.g umul_high of 32-bit
+         * requires computing at 64-bit */
+        if (midgard_is_integer_out_op(ins->op) && ins->outmod == midgard_outmod_int_high) {
+                max_bitsize *= 2;
+                assert(max_bitsize <= 64);
+        }
+
         return max_bitsize;
 }
 

src/panfrost/midgard/midgard_schedule.c

diff --git a/src/panfrost/midgard/midgard_schedule.c b/src/panfrost/midgard/midgard_schedule.c
index 3391e53..63b1d78 100644
--- a/src/panfrost/midgard/midgard_schedule.c
+++ b/src/panfrost/midgard/midgard_schedule.c
@@ -212,6 +212,9 @@
         if (ains->src[1] != ~0)
                 could_scalar &= (sz1 == 16) || (sz1 == 32);
 
+        if (midgard_is_integer_out_op(ains->op) && ains->outmod != midgard_outmod_int_wrap)
+                return false;
+
         return could_scalar;
 }