commit d74824bdd01b2a76b310e1275a1114d39833a708
author Zheng Xu <zheng.xu@arm.com> Tue Aug 12 17:19:12 2014 +0800
committer Andreas Gampe <agampe@google.com> Tue Aug 12 08:39:05 2014 -0700
tree 6b659b89325d8f7671352a6ee8644363d2758383
parent 8c6c52110c5afd438741694520203a6d7e81a2a4

AArch64: Fix art_quick_string_compareto.

Though __memcmp16() is implemented in the same module as the caller, it
is still possible that the toolchain would put __memcmp16() into plt. In
that case, IP registers can be trashed when loading the function address.
Use x14/x15 to replace IP0/IP1.

Bug: 16974467

(cherry picked from commit 62ddb328860e907eb76ccd3abed63ba75438fea8)

Change-Id: I40e39d075860bc78624ce6ef8b4f8e33e57fc58c

runtime/arch/arm64/quick_entrypoints_arm64.S

diff --git a/runtime/arch/arm64/quick_entrypoints_arm64.S b/runtime/arch/arm64/quick_entrypoints_arm64.S
index 04be4a2..62ae099 100644
--- a/runtime/arch/arm64/quick_entrypoints_arm64.S
+++ b/runtime/arch/arm64/quick_entrypoints_arm64.S
@@ -1843,17 +1843,17 @@
     ret
 
 .Ldo_memcmp16:
-    mov xIP0, x0                  // Save x0 and LR. __memcmp16 does not use these temps.
-    mov xIP1, xLR                 //                 TODO: Codify and check that?
+    mov x14, x0                  // Save x0 and LR. __memcmp16 does not use these temps.
+    mov x15, xLR                 //                 TODO: Codify and check that?
 
     mov x0, x2
     uxtw x2, w3
     bl __memcmp16
 
-    mov xLR, xIP1                 // Restore LR.
+    mov xLR, x15                 // Restore LR.
 
     cmp x0, #0                   // Check the memcmp difference.
-    csel x0, x0, xIP0, ne         // x0 := x0 != 0 ? xIP0(prev x0=length diff) : x1.
+    csel x0, x0, x14, ne         // x0 := x0 != 0 ? x14(prev x0=length diff) : x1.
     ret
 END art_quick_string_compareto