diff options
| -rw-r--r-- | llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp | 10 | ||||
| -rw-r--r-- | llvm/test/Transforms/InstCombine/ctlz-cttz-bitreverse.ll | 30 |
2 files changed, 21 insertions, 19 deletions
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp index e6f7e623067..c2506798660 100644 --- a/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp +++ b/llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp @@ -1324,12 +1324,20 @@ static Instruction *foldCttzCtlz(IntrinsicInst &II, InstCombiner &IC) { assert((II.getIntrinsicID() == Intrinsic::cttz || II.getIntrinsicID() == Intrinsic::ctlz) && "Expected cttz or ctlz intrinsic"); + bool IsTZ = II.getIntrinsicID() == Intrinsic::cttz; Value *Op0 = II.getArgOperand(0); + Value *X; + // ctlz(bitreverse(x)) -> cttz(x) + // cttz(bitreverse(x)) -> ctlz(x) + if (match(Op0, m_BitReverse(m_Value(X)))) { + Intrinsic::ID ID = IsTZ ? Intrinsic::ctlz : Intrinsic::cttz; + Function *F = Intrinsic::getDeclaration(II.getModule(), ID, II.getType()); + return CallInst::Create(F, {X, II.getArgOperand(1)}); + } KnownBits Known = IC.computeKnownBits(Op0, 0, &II); // Create a mask for bits above (ctlz) or below (cttz) the first known one. - bool IsTZ = II.getIntrinsicID() == Intrinsic::cttz; unsigned PossibleZeros = IsTZ ? Known.countMaxTrailingZeros() : Known.countMaxLeadingZeros(); unsigned DefiniteZeros = IsTZ ? Known.countMinTrailingZeros() diff --git a/llvm/test/Transforms/InstCombine/ctlz-cttz-bitreverse.ll b/llvm/test/Transforms/InstCombine/ctlz-cttz-bitreverse.ll index 2779f96e3a5..fb745959829 100644 --- a/llvm/test/Transforms/InstCombine/ctlz-cttz-bitreverse.ll +++ b/llvm/test/Transforms/InstCombine/ctlz-cttz-bitreverse.ll @@ -3,9 +3,8 @@ define i32 @ctlz_true_bitreverse(i32 %x) { ; CHECK-LABEL: @ctlz_true_bitreverse( -; CHECK-NEXT: [[A:%.*]] = tail call i32 @llvm.bitreverse.i32(i32 [[X:%.*]]) -; CHECK-NEXT: [[B:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[A]], i1 true), !range !0 -; CHECK-NEXT: ret i32 [[B]] +; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.cttz.i32(i32 [[X:%.*]], i1 true), !range !0 +; CHECK-NEXT: ret i32 [[TMP1]] ; %a = tail call i32 @llvm.bitreverse.i32(i32 %x) %b = tail call i32 @llvm.ctlz.i32(i32 %a, i1 true) @@ -14,9 +13,8 @@ define i32 @ctlz_true_bitreverse(i32 %x) { define <2 x i64> @ctlz_true_bitreverse_vec(<2 x i64> %x) { ; CHECK-LABEL: @ctlz_true_bitreverse_vec( -; CHECK-NEXT: [[A:%.*]] = tail call <2 x i64> @llvm.bitreverse.v2i64(<2 x i64> [[X:%.*]]) -; CHECK-NEXT: [[B:%.*]] = tail call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> [[A]], i1 true) -; CHECK-NEXT: ret <2 x i64> [[B]] +; CHECK-NEXT: [[TMP1:%.*]] = call <2 x i64> @llvm.cttz.v2i64(<2 x i64> [[X:%.*]], i1 true) +; CHECK-NEXT: ret <2 x i64> [[TMP1]] ; %a = tail call <2 x i64> @llvm.bitreverse.v2i64(<2 x i64> %x) %b = tail call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> %a, i1 true) @@ -25,9 +23,8 @@ define <2 x i64> @ctlz_true_bitreverse_vec(<2 x i64> %x) { define i32 @ctlz_false_bitreverse(i32 %x) { ; CHECK-LABEL: @ctlz_false_bitreverse( -; CHECK-NEXT: [[A:%.*]] = tail call i32 @llvm.bitreverse.i32(i32 [[X:%.*]]) -; CHECK-NEXT: [[B:%.*]] = tail call i32 @llvm.ctlz.i32(i32 [[A]], i1 false), !range !0 -; CHECK-NEXT: ret i32 [[B]] +; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.cttz.i32(i32 [[X:%.*]], i1 false), !range !0 +; CHECK-NEXT: ret i32 [[TMP1]] ; %a = tail call i32 @llvm.bitreverse.i32(i32 %x) %b = tail call i32 @llvm.ctlz.i32(i32 %a, i1 false) @@ -36,9 +33,8 @@ define i32 @ctlz_false_bitreverse(i32 %x) { define i32 @cttz_true_bitreverse(i32 %x) { ; CHECK-LABEL: @cttz_true_bitreverse( -; CHECK-NEXT: [[A:%.*]] = tail call i32 @llvm.bitreverse.i32(i32 [[X:%.*]]) -; CHECK-NEXT: [[B:%.*]] = tail call i32 @llvm.cttz.i32(i32 [[A]], i1 true), !range !0 -; CHECK-NEXT: ret i32 [[B]] +; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 true), !range !0 +; CHECK-NEXT: ret i32 [[TMP1]] ; %a = tail call i32 @llvm.bitreverse.i32(i32 %x) %b = tail call i32 @llvm.cttz.i32(i32 %a, i1 true) @@ -47,9 +43,8 @@ define i32 @cttz_true_bitreverse(i32 %x) { define <2 x i64> @cttz_true_bitreverse_vec(<2 x i64> %x) { ; CHECK-LABEL: @cttz_true_bitreverse_vec( -; CHECK-NEXT: [[A:%.*]] = tail call <2 x i64> @llvm.bitreverse.v2i64(<2 x i64> [[X:%.*]]) -; CHECK-NEXT: [[B:%.*]] = tail call <2 x i64> @llvm.cttz.v2i64(<2 x i64> [[A]], i1 true) -; CHECK-NEXT: ret <2 x i64> [[B]] +; CHECK-NEXT: [[TMP1:%.*]] = call <2 x i64> @llvm.ctlz.v2i64(<2 x i64> [[X:%.*]], i1 true) +; CHECK-NEXT: ret <2 x i64> [[TMP1]] ; %a = tail call <2 x i64> @llvm.bitreverse.v2i64(<2 x i64> %x) %b = tail call <2 x i64> @llvm.cttz.v2i64(<2 x i64> %a, i1 true) @@ -58,9 +53,8 @@ define <2 x i64> @cttz_true_bitreverse_vec(<2 x i64> %x) { define i32 @cttz_false_bitreverse(i32 %x) { ; CHECK-LABEL: @cttz_false_bitreverse( -; CHECK-NEXT: [[A:%.*]] = tail call i32 @llvm.bitreverse.i32(i32 [[X:%.*]]) -; CHECK-NEXT: [[B:%.*]] = tail call i32 @llvm.cttz.i32(i32 [[A]], i1 false), !range !0 -; CHECK-NEXT: ret i32 [[B]] +; CHECK-NEXT: [[TMP1:%.*]] = call i32 @llvm.ctlz.i32(i32 [[X:%.*]], i1 false), !range !0 +; CHECK-NEXT: ret i32 [[TMP1]] ; %a = tail call i32 @llvm.bitreverse.i32(i32 %x) %b = tail call i32 @llvm.cttz.i32(i32 %a, i1 false) |
