6 Commits

Author	SHA1	Message	Date
Paul Redmond	9d86a4a3b6	Transform (sub 0, (zext bool to A)) to (sext bool to A) and ... (sub 0, (sext bool to A)) to (zext bool to A). Patch by Muhammad Ahmad Reviewed by Duncan Sands llvm-svn: 173093	2013-01-21 21:57:20 +00:00
Evan Cheng	319be53a1f	Remove a instcombine transform that (no longer?) makes sense: ... // C - zext(bool) -> bool ? C - 1 : C if (ZExtInst *ZI = dyn_cast<ZExtInst>(Op1)) if (ZI->getSrcTy()->isIntegerTy(1)) return SelectInst::Create(ZI->getOperand(0), SubOne(C), C); This ends up forming sext i1 instructions that codegen to terrible code. e.g. int blah(_Bool x, _Bool y) { return (x - y) + 1; } => movzbl %dil, %eax movzbl %sil, %ecx shll $31, %ecx sarl $31, %ecx leal 1(%rax,%rcx), %eax ret Without the rule, llvm now generates: movzbl %sil, %ecx movzbl %dil, %eax incl %eax subl %ecx, %eax ret It also helps with ARM (and pretty much any target that doesn't have a sext i1 :-). The transformation was done as part of Eli's r75531. He has given the ok to remove it. rdar://11748024 llvm-svn: 159230	2012-06-26 22:03:13 +00:00
Dan Gohman	72a13d2476	Use opt -S instead of piping bitcode output through llvm-dis. ... llvm-svn: 81257	2009-09-08 22:34:10 +00:00
Dan Gohman	9737a63ed8	Change these tests to feed the assembly files to opt directly, instead ... of using llvm-as, now that opt supports this. llvm-svn: 81226	2009-09-08 16:50:01 +00:00
Eli Friedman	116e3b3ef1	Fix bug in run-line. ... llvm-svn: 75534	2009-07-13 22:31:30 +00:00
Eli Friedman	7e1716dc9d	Canonicalize boolean +/- a constant to a select. ... (I think it's reasonably clear that we want to have a canonical form for constructs like this; if anyone thinks that a select is not the best canonical form, please tell me.) llvm-svn: 75531	2009-07-13 22:27:52 +00:00