[compiler-rt] 966d564 - asan_static x86-64: Support 64-bit ASAN_SHADOW_OFFSET_CONST redux (#76185)

[via llvm-commits]

Author: Dan McGregor
Date: 2023-12-24T20:37:35-08:00
New Revision: 966d564e43e650b9c34f9c67829d3947f52add91

URL: https://github.com/llvm/llvm-project/commit/966d564e43e650b9c34f9c67829d3947f52add91
DIFF: https://github.com/llvm/llvm-project/commit/966d564e43e650b9c34f9c67829d3947f52add91.diff

LOG: asan_static x86-64: Support 64-bit ASAN_SHADOW_OFFSET_CONST redux (#76185)

Similar to b9935bb02a50, but also apply a similar change to
ACCESS_CHECK_ADD.

If ASAN_SHADOW_OFFSET_CONST cannot be encoded as a displacement, switch
to `movabsq` and the register offset variant of cmp.

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 e44587ac4331c7..9c5289856d8ae6 100644
--- a/compiler-rt/lib/asan/asan_rtl_x86_64.S
+++ b/compiler-rt/lib/asan/asan_rtl_x86_64.S
@@ -89,7 +89,12 @@ ENDF
 #define ASAN_MEMORY_ACCESS_CHECK_ADD(reg, op, s, c) \
         mov    %##reg,%r10 ;\
         shr    $0x3,%r10 ;\
+        .if ASAN_SHADOW_OFFSET_CONST < 0x80000000  ;\
         ##c    $0x0,ASAN_SHADOW_OFFSET_CONST(%r10) ;\
+        .else                                      ;\
+        movabsq $ASAN_SHADOW_OFFSET_CONST,%r11     ;\
+        ##c    $0x0,(%r10,%r11)                    ;\
+        .endif                                     ;\
         jne    FLABEL(reg, op, s, add) ;\
         retq  ;\