[compiler-rt] 9ddb215 - [asan] Remove unnecessary spill in optimized callbacks

[Vitaly Buka via llvm-commits]

Author: Vitaly Buka
Date: 2023-08-23T16:59:57-07:00
New Revision: 9ddb2157e3c04a601d7d9764f99f4df3c2fa80c2

URL: https://github.com/llvm/llvm-project/commit/9ddb2157e3c04a601d7d9764f99f4df3c2fa80c2
DIFF: https://github.com/llvm/llvm-project/commit/9ddb2157e3c04a601d7d9764f99f4df3c2fa80c2.diff

LOG: [asan] Remove unnecessary spill in optimized callbacks

We can use r11 scratch registers for calculations.

It does not result in any performance improvements, as the spill is on
the slow path of partial granules.

See X86AsmPrinter::LowerASAN_CHECK_MEMACCESS for callers.

Reviewed By: kstoimenov

Differential Revision: https://reviews.llvm.org/D158525

Added: 
    

Modified: 
    compiler-rt/lib/asan/asan_rtl_x86_64.S

Removed: 
    


################################################################################
diff  --git a/compiler-rt/lib/asan/asan_rtl_x86_64.S b/compiler-rt/lib/asan/asan_rtl_x86_64.S
index d93b5ed2a7fe34..0b7363018f425f 100644
--- a/compiler-rt/lib/asan/asan_rtl_x86_64.S
+++ b/compiler-rt/lib/asan/asan_rtl_x86_64.S
@@ -35,35 +35,29 @@ RLABEL(reg, op, s, add): ;\
 
 #define ASAN_MEMORY_ACCESS_EXTRA_CHECK_1(reg, op, i) \
 CLABEL(reg, op, 1, i): ;\
-        push   %rcx ;\
-        mov    %##reg,%rcx ;\
-        and    $0x7,%ecx ;\
-        cmp    %r10d,%ecx ;\
-        pop    %rcx ;\
+        mov    %##reg,%r11 ;\
+        and    $0x7,%r11d ;\
+        cmp    %r10d,%r11d ;\
         jl     RLABEL(reg, op, 1, i);\
         mov    %##reg,%rdi ;\
         jmp    __asan_report_##op##1_asm ;\
 
 #define ASAN_MEMORY_ACCESS_EXTRA_CHECK_2(reg, op, i) \
 CLABEL(reg, op, 2, i): ;\
-        push   %rcx ;\
-        mov    %##reg,%rcx ;\
-        and    $0x7,%ecx ;\
-        add    $0x1,%ecx ;\
-        cmp    %r10d,%ecx ;\
-        pop    %rcx ;\
+        mov    %##reg,%r11 ;\
+        and    $0x7,%r11d ;\
+        add    $0x1,%r11d ;\
+        cmp    %r10d,%r11d ;\
         jl     RLABEL(reg, op, 2, i);\
         mov    %##reg,%rdi ;\
         jmp    __asan_report_##op##2_asm ;\
 
 #define ASAN_MEMORY_ACCESS_EXTRA_CHECK_4(reg, op, i) \
 CLABEL(reg, op, 4, i): ;\
-        push   %rcx ;\
-        mov    %##reg,%rcx ;\
-        and    $0x7,%ecx ;\
-        add    $0x3,%ecx ;\
-        cmp    %r10d,%ecx ;\
-        pop    %rcx ;\
+        mov    %##reg,%r11 ;\
+        and    $0x7,%r11d ;\
+        add    $0x3,%r11d ;\
+        cmp    %r10d,%r11d ;\
         jl     RLABEL(reg, op, 4, i);\
         mov    %##reg,%rdi ;\
         jmp    __asan_report_##op##4_asm ;\