6502/llvm-6502
1
0
Fork 0
mirror of https://github.com/c64scene-ar/llvm-6502.git synced 2025-07-17 03:24:34 +00:00
Code Issues Projects Releases Wiki Activity

Use a memcpy so that type based alias analysis sees the change.

Browse Source 
The other option would be to do something like

if (that.isSingleWord())
  VAL = that.VAL;
else
  pVal = that.pVal

This bug was causing 86TTI::getIntImmCost to be miscompiled in a LTO
bootstrap in stage2, causing the build of stage3 to fail.

LLVM is getting quiet good at exploiting this. Not sure if there is anything
a sanitizer could do to help

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222294 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Rafael Espindola
2014-11-19 01:02:22 +00:00
parent d8e31c73cd
commit 28b45aa83e
1 changed files with 3 additions and 1 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
include/llvm/ADT/APInt.h
View File

@@ -665,7 +665,9 @@ public:
delete[] pVal; delete[] pVal;
} }
VAL = that.VAL; // Use memcpy so that type based alias analysis sees both VAL and pVal
// as modified.
memcpy(&VAL, &that.VAL, sizeof(uint64_t));
// If 'this == &that', avoid zeroing our own bitwidth by storing to 'that' // If 'this == &that', avoid zeroing our own bitwidth by storing to 'that'
// first. // first.