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https://github.com/c64scene-ar/llvm-6502.git
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4053b1e30b
typically cost 1 cycle) instead of shld/shrd instruction (which are typically
6 or more cycles). This also saves code space.
For example, instead of emitting:
rotr:
mov %EAX, DWORD PTR [%ESP + 4]
mov %CL, BYTE PTR [%ESP + 8]
shrd %EAX, %EAX, %CL
ret
rotli:
mov %EAX, DWORD PTR [%ESP + 4]
shrd %EAX, %EAX, 27
ret
Emit:
rotr32:
mov %CL, BYTE PTR [%ESP + 8]
mov %EAX, DWORD PTR [%ESP + 4]
ror %EAX, %CL
ret
rotli32:
mov %EAX, DWORD PTR [%ESP + 4]
ror %EAX, 27
ret
We also emit byte rotate instructions which do not have a sh[lr]d counterpart
at all.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19692 91177308-0d34-0410-b5e6-96231b3b80d8
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| .. | ||
| .cvsignore | ||
| Makefile | ||
| X86.h | ||
| X86.td | ||
| X86AsmPrinter.cpp | ||
| X86CodeEmitter.cpp | ||
| X86FloatingPoint.cpp | ||
| X86InstrBuilder.h | ||
| X86InstrInfo.cpp | ||
| X86InstrInfo.h | ||
| X86InstrInfo.td | ||
| X86ISelPattern.cpp | ||
| X86ISelSimple.cpp | ||
| X86JITInfo.cpp | ||
| X86JITInfo.h | ||
| X86PeepholeOpt.cpp | ||
| X86RegisterInfo.cpp | ||
| X86RegisterInfo.h | ||
| X86RegisterInfo.td | ||
| X86Relocations.h | ||
| X86TargetMachine.cpp | ||
| X86TargetMachine.h | ||