forked from OSchip/llvm-project
2e56e89452
int %test_cpuid(int %op) {
%B = alloca int
%C = alloca int
%D = alloca int
%A = call int asm "cpuid", "=eax,==ebx,==ecx,==edx,eax"(int* %B, int* %C, int* %D, int %op)
%Bv = load int* %B
%Cv = load int* %C
%Dv = load int* %D
%x = add int %A, %Bv
%y = add int %x, %Cv
%z = add int %y, %Dv
ret int %z
}
to this:
_test_cpuid:
sub %ESP, 16
mov DWORD PTR [%ESP], %EBX
mov %EAX, DWORD PTR [%ESP + 20]
cpuid
mov DWORD PTR [%ESP + 8], %ECX
mov DWORD PTR [%ESP + 12], %EBX
mov DWORD PTR [%ESP + 4], %EDX
mov %ECX, DWORD PTR [%ESP + 12]
add %EAX, %ECX
mov %ECX, DWORD PTR [%ESP + 8]
add %EAX, %ECX
mov %ECX, DWORD PTR [%ESP + 4]
add %EAX, %ECX
mov %EBX, DWORD PTR [%ESP]
add %ESP, 16
ret
... note the proper register allocation. :)
it is unclear to me why the loads aren't folded into the adds.
llvm-svn: 25827
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|---|---|---|
| .. | ||
| SelectionDAG | ||
| AsmPrinter.cpp | ||
| BranchFolding.cpp | ||
| DwarfWriter.cpp | ||
| ELFWriter.cpp | ||
| IntrinsicLowering.cpp | ||
| LiveInterval.cpp | ||
| LiveIntervalAnalysis.cpp | ||
| LiveVariables.cpp | ||
| MachineBasicBlock.cpp | ||
| MachineCodeEmitter.cpp | ||
| MachineDebugInfo.cpp | ||
| MachineFunction.cpp | ||
| MachineInstr.cpp | ||
| Makefile | ||
| PHIElimination.cpp | ||
| Passes.cpp | ||
| PhysRegTracker.h | ||
| PrologEpilogInserter.cpp | ||
| RegAllocLinearScan.cpp | ||
| RegAllocLocal.cpp | ||
| RegAllocSimple.cpp | ||
| TwoAddressInstructionPass.cpp | ||
| UnreachableBlockElim.cpp | ||
| ValueTypes.cpp | ||
| VirtRegMap.cpp | ||
| VirtRegMap.h | ||