From fc95a84f5d0abae681d6976bc1003e64de2f871e Mon Sep 17 00:00:00 2001 From: Roman Lebedev Date: Sat, 14 Jul 2018 16:44:43 +0000 Subject: [PATCH] [InstCombine] Fold x u> x & C to x u> C https://bugs.llvm.org/show_bug.cgi?id=38123 https://rise4fun.com/Alive/JvS This pattern is not commutative. But InstSimplify will already have taken care of the 'commutative' variant. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@337100 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../InstCombine/InstCombineCompares.cpp | 5 +++ ...t-low-bit-mask-and-icmp-ugt-to-icmp-ugt.ll | 34 ++++++++----------- 2 files changed, 19 insertions(+), 20 deletions(-) diff --git a/lib/Transforms/InstCombine/InstCombineCompares.cpp b/lib/Transforms/InstCombine/InstCombineCompares.cpp index eec8fadedb2..1024cbafaaa 100644 --- a/lib/Transforms/InstCombine/InstCombineCompares.cpp +++ b/lib/Transforms/InstCombine/InstCombineCompares.cpp @@ -2892,6 +2892,11 @@ static Value *foldICmpWithLowBitMaskedVal(ICmpInst &I, // x & (-1 >> y) != x -> x u> (-1 >> y) DstPred = ICmpInst::Predicate::ICMP_UGT; break; + case ICmpInst::Predicate::ICMP_UGT: + // x u> x & (-1 >> y) -> x u> (-1 >> y) + assert(X == I.getOperand(0) && "instsimplify took care of commut. variant"); + DstPred = ICmpInst::Predicate::ICMP_UGT; + break; case ICmpInst::Predicate::ICMP_UGE: // x & (-1 >> y) u>= x -> x u<= (-1 >> y) assert(X == I.getOperand(1) && "instsimplify took care of commut. variant"); diff --git a/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ugt-to-icmp-ugt.ll b/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ugt-to-icmp-ugt.ll index fb4bace803e..7512b72f2a7 100644 --- a/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ugt-to-icmp-ugt.ll +++ b/test/Transforms/InstCombine/canonicalize-constant-low-bit-mask-and-icmp-ugt-to-icmp-ugt.ll @@ -20,9 +20,8 @@ declare <3 x i8> @gen3x8() define i1 @p0() { ; CHECK-LABEL: @p0( ; CHECK-NEXT: [[X:%.*]] = call i8 @gen8() -; CHECK-NEXT: [[TMP0:%.*]] = and i8 [[X]], 3 -; CHECK-NEXT: [[RET:%.*]] = icmp ugt i8 [[X]], [[TMP0]] -; CHECK-NEXT: ret i1 [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[X]], 3 +; CHECK-NEXT: ret i1 [[TMP1]] ; %x = call i8 @gen8() %tmp0 = and i8 %x, 3 @@ -34,9 +33,8 @@ define i1 @pv(i8 %y) { ; CHECK-LABEL: @pv( ; CHECK-NEXT: [[X:%.*]] = call i8 @gen8() ; CHECK-NEXT: [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]] -; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[TMP0]], [[X]] -; CHECK-NEXT: [[RET:%.*]] = icmp ugt i8 [[X]], [[TMP1]] -; CHECK-NEXT: ret i1 [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[X]], [[TMP0]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %x = call i8 @gen8() %tmp0 = lshr i8 -1, %y @@ -52,9 +50,8 @@ define i1 @pv(i8 %y) { define <2 x i1> @p1_vec_splat() { ; CHECK-LABEL: @p1_vec_splat( ; CHECK-NEXT: [[X:%.*]] = call <2 x i8> @gen2x8() -; CHECK-NEXT: [[TMP0:%.*]] = and <2 x i8> [[X]], -; CHECK-NEXT: [[RET:%.*]] = icmp ugt <2 x i8> [[X]], [[TMP0]] -; CHECK-NEXT: ret <2 x i1> [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt <2 x i8> [[X]], +; CHECK-NEXT: ret <2 x i1> [[TMP1]] ; %x = call <2 x i8> @gen2x8() %tmp0 = and <2 x i8> %x, @@ -65,9 +62,8 @@ define <2 x i1> @p1_vec_splat() { define <2 x i1> @p2_vec_nonsplat() { ; CHECK-LABEL: @p2_vec_nonsplat( ; CHECK-NEXT: [[X:%.*]] = call <2 x i8> @gen2x8() -; CHECK-NEXT: [[TMP0:%.*]] = and <2 x i8> [[X]], -; CHECK-NEXT: [[RET:%.*]] = icmp ugt <2 x i8> [[X]], [[TMP0]] -; CHECK-NEXT: ret <2 x i1> [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt <2 x i8> [[X]], +; CHECK-NEXT: ret <2 x i1> [[TMP1]] ; %x = call <2 x i8> @gen2x8() %tmp0 = and <2 x i8> %x, ; doesn't have to be splat. @@ -78,9 +74,8 @@ define <2 x i1> @p2_vec_nonsplat() { define <3 x i1> @p3_vec_splat_undef() { ; CHECK-LABEL: @p3_vec_splat_undef( ; CHECK-NEXT: [[X:%.*]] = call <3 x i8> @gen3x8() -; CHECK-NEXT: [[TMP0:%.*]] = and <3 x i8> [[X]], -; CHECK-NEXT: [[RET:%.*]] = icmp ugt <3 x i8> [[X]], [[TMP0]] -; CHECK-NEXT: ret <3 x i1> [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt <3 x i8> [[X]], +; CHECK-NEXT: ret <3 x i1> [[TMP1]] ; %x = call <3 x i8> @gen3x8() %tmp0 = and <3 x i8> %x, @@ -109,9 +104,8 @@ define i1 @cv0(i8 %y) { ; CHECK-LABEL: @cv0( ; CHECK-NEXT: [[X:%.*]] = call i8 @gen8() ; CHECK-NEXT: [[TMP0:%.*]] = lshr i8 -1, [[Y:%.*]] -; CHECK-NEXT: [[TMP1:%.*]] = and i8 [[TMP0]], [[X]] -; CHECK-NEXT: [[RET:%.*]] = icmp ugt i8 [[X]], [[TMP1]] -; CHECK-NEXT: ret i1 [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[X]], [[TMP0]] +; CHECK-NEXT: ret i1 [[TMP1]] ; %x = call i8 @gen8() %tmp0 = lshr i8 -1, %y @@ -153,8 +147,8 @@ define i1 @oneuse0() { ; CHECK-NEXT: [[X:%.*]] = call i8 @gen8() ; CHECK-NEXT: [[TMP0:%.*]] = and i8 [[X]], 3 ; CHECK-NEXT: call void @use8(i8 [[TMP0]]) -; CHECK-NEXT: [[RET:%.*]] = icmp ugt i8 [[X]], [[TMP0]] -; CHECK-NEXT: ret i1 [[RET]] +; CHECK-NEXT: [[TMP1:%.*]] = icmp ugt i8 [[X]], 3 +; CHECK-NEXT: ret i1 [[TMP1]] ; %x = call i8 @gen8() %tmp0 = and i8 %x, 3 -- 2.50.1