Displaying 2 results from an estimated 2 matches for "a7b84298".
2013 Sep 13
0
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
> I think your real problem is that garbage went into ECX instead of 0 and
> caused cpuid to return 0.
Ah, that looks very likely. The value seems to come from "xorl %eax,
%eax" in both good object files, but a previous cpuid in the bad one.
Excellent work Craig, I suspect that would have taken me days to find.
Tim.
2013 Sep 13
2
[LLVMdev] [PATCH] Detect Haswell subarchitecture (i.e. using -march=native)
Actually there is no miscompile there as esi isn't needed. The flags are
which the cmove is using.
342: shr esi,0x5
345: lea rbp,[rip+0x0] # 34c <llvm::sys::getHostCPUName()+0xbc>
34c: lea r12,[rip+0x0] # 353 <llvm::sys::getHostCPUName()+0xc3>
353: cmove rbp,r12 <- this is dependent on the flags from the shift.
I think your real problem is