[llvm-commits] [llvm] r92745 - in /llvm/trunk: lib/Transforms/InstCombine/InstCombineCompares.cpp test/Transforms/InstCombine/intrinsics.ll
Chris Lattner
sabre at nondot.org
Tue Jan 5 10:09:57 PST 2010
Author: lattner
Date: Tue Jan 5 12:09:56 2010
New Revision: 92745
URL: http://llvm.org/viewvc/llvm-project?rev=92745&view=rev
Log:
optimize comparisons against cttz/ctlz/ctpop, patch by Alastair Lynn!
Modified:
llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
llvm/trunk/test/Transforms/InstCombine/intrinsics.ll
Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp?rev=92745&r1=92744&r2=92745&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCompares.cpp Tue Jan 5 12:09:56 2010
@@ -1418,11 +1418,33 @@
}
} else if (IntrinsicInst *II = dyn_cast<IntrinsicInst>(LHSI)) {
// Handle icmp {eq|ne} <intrinsic>, intcst.
- if (II->getIntrinsicID() == Intrinsic::bswap) {
+ switch (II->getIntrinsicID()) {
+ case Intrinsic::bswap:
Worklist.Add(II);
ICI.setOperand(0, II->getOperand(1));
ICI.setOperand(1, ConstantInt::get(II->getContext(), RHSV.byteSwap()));
return &ICI;
+ case Intrinsic::ctlz:
+ case Intrinsic::cttz:
+ // ctz(A) == bitwidth(a) -> A == 0 and likewise for !=
+ if (RHSV == RHS->getType()->getBitWidth()) {
+ Worklist.Add(II);
+ ICI.setOperand(0, II->getOperand(1));
+ ICI.setOperand(1, ConstantInt::get(RHS->getType(), 0));
+ return &ICI;
+ }
+ break;
+ case Intrinsic::ctpop:
+ // popcount(A) == 0 -> A == 0 and likewise for !=
+ if (RHS->isZero()) {
+ Worklist.Add(II);
+ ICI.setOperand(0, II->getOperand(1));
+ ICI.setOperand(1, RHS);
+ return &ICI;
+ }
+ break;
+ default:
+ break;
}
}
}
Modified: llvm/trunk/test/Transforms/InstCombine/intrinsics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/intrinsics.ll?rev=92745&r1=92744&r2=92745&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/intrinsics.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/intrinsics.ll Tue Jan 5 12:09:56 2010
@@ -6,6 +6,8 @@
declare %overflow.result @llvm.umul.with.overflow.i8(i8, i8)
declare double @llvm.powi.f64(double, i32) nounwind readonly
declare i32 @llvm.cttz.i32(i32) nounwind readnone
+declare i32 @llvm.ctlz.i32(i32) nounwind readnone
+declare i32 @llvm.ctpop.i32(i32) nounwind readnone
declare i8 @llvm.ctlz.i8(i8) nounwind readnone
define i8 @test1(i8 %A, i8 %B) {
@@ -99,8 +101,7 @@
; CHECK: volatile store double %V
}
-define i32 @cttz(i32 %a)
-{
+define i32 @cttz(i32 %a) {
entry:
%or = or i32 %a, 8
%and = and i32 %or, -8
@@ -111,8 +112,7 @@
; CHECK-NEXT: ret i32 3
}
-define i8 @ctlz(i8 %a)
-{
+define i8 @ctlz(i8 %a) {
entry:
%or = or i8 %a, 32
%and = and i8 %or, 63
@@ -122,3 +122,25 @@
; CHECK-NEXT: entry:
; CHECK-NEXT: ret i8 2
}
+
+define void @cmp.simplify(i32 %a, i32 %b, i1* %c) {
+entry:
+ %lz = tail call i32 @llvm.ctlz.i32(i32 %a) nounwind readnone
+ %lz.cmp = icmp eq i32 %lz, 32
+ volatile store i1 %lz.cmp, i1* %c
+ %tz = tail call i32 @llvm.cttz.i32(i32 %a) nounwind readnone
+ %tz.cmp = icmp ne i32 %tz, 32
+ volatile store i1 %tz.cmp, i1* %c
+ %pop = tail call i32 @llvm.ctpop.i32(i32 %b) nounwind readnone
+ %pop.cmp = icmp eq i32 %pop, 0
+ volatile store i1 %pop.cmp, i1* %c
+ ret void
+; CHECK: @cmp.simplify
+; CHECK-NEXT: entry:
+; CHECK-NEXT: %lz.cmp = icmp eq i32 %a, 0
+; CHECK-NEXT: volatile store i1 %lz.cmp, i1* %c
+; CHECK-NEXT: %tz.cmp = icmp ne i32 %a, 0
+; CHECK-NEXT: volatile store i1 %tz.cmp, i1* %c
+; CHECK-NEXT: %pop.cmp = icmp eq i32 %b, 0
+; CHECK-NEXT: volatile store i1 %pop.cmp, i1* %c
+}
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