From 9e6a1814c9f5c88bf74272971f28ea4cd81fd735 Mon Sep 17 00:00:00 2001 From: David Majnemer Date: Wed, 26 Nov 2014 23:00:38 +0000 Subject: [PATCH] Revert "Added inst combine transforms for single bit tests from Chris's note" This reverts commit r210006, it miscompiled libapr which is used in who knows how many projects. A test has been added to ensure that we don't regress again. I'll work on a rewrite of what the optimization was trying to do later. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@222856 91177308-0d34-0410-b5e6-96231b3b80d8 --- .../InstCombine/InstCombineSelect.cpp | 29 +---- test/Transforms/InstCombine/select.ll | 115 ++---------------- 2 files changed, 11 insertions(+), 133 deletions(-) diff --git a/lib/Transforms/InstCombine/InstCombineSelect.cpp b/lib/Transforms/InstCombine/InstCombineSelect.cpp index 2c185264faf..8e2a7d5ce65 100644 --- a/lib/Transforms/InstCombine/InstCombineSelect.cpp +++ b/lib/Transforms/InstCombine/InstCombineSelect.cpp @@ -389,15 +389,7 @@ static Value *SimplifyWithOpReplaced(Value *V, Value *Op, Value *RepOp, /// 1. The icmp predicate is inverted /// 2. The select operands are reversed /// 3. The magnitude of C2 and C1 are flipped -/// -/// This also tries to turn -/// --- Single bit tests: -/// if ((x & C) == 0) x |= C to x |= C -/// if ((x & C) != 0) x ^= C to x &= ~C -/// if ((x & C) == 0) x ^= C to x |= C -/// if ((x & C) != 0) x &= ~C to x &= ~C -/// if ((x & C) == 0) x &= ~C to nothing -static Value *foldSelectICmpAndOr(SelectInst &SI, Value *TrueVal, +static Value *foldSelectICmpAndOr(const SelectInst &SI, Value *TrueVal, Value *FalseVal, InstCombiner::BuilderTy *Builder) { const ICmpInst *IC = dyn_cast(SI.getCondition()); @@ -416,25 +408,6 @@ static Value *foldSelectICmpAndOr(SelectInst &SI, Value *TrueVal, return nullptr; const APInt *C2; - if (match(TrueVal, m_Specific(X))) { - // if ((X & C) != 0) X ^= C becomes X &= ~C - if (match(FalseVal, m_Xor(m_Specific(X), m_APInt(C2))) && C1 == C2) - return Builder->CreateAnd(X, ~(*C1)); - // if ((X & C) != 0) X &= ~C becomes X &= ~C - if (match(FalseVal, m_And(m_Specific(X), m_APInt(C2))) && *C1 == ~(*C2)) - return FalseVal; - } else if (match(FalseVal, m_Specific(X))) { - // if ((X & C) == 0) X ^= C becomes X |= C - if (match(TrueVal, m_Xor(m_Specific(X), m_APInt(C2))) && C1 == C2) - return Builder->CreateOr(X, *C1); - // if ((X & C) == 0) X &= ~C becomes nothing - if (match(TrueVal, m_And(m_Specific(X), m_APInt(C2))) && *C1 == ~(*C2)) - return X; - // if ((X & C) == 0) X |= C becomes X |= C - if (match(TrueVal, m_Or(m_Specific(X), m_APInt(C2))) && C1 == C2) - return TrueVal; - } - bool OrOnTrueVal = false; bool OrOnFalseVal = match(FalseVal, m_Or(m_Specific(TrueVal), m_Power2(C2))); if (!OrOnFalseVal) diff --git a/test/Transforms/InstCombine/select.ll b/test/Transforms/InstCombine/select.ll index c8ae024c293..8444677d19a 100644 --- a/test/Transforms/InstCombine/select.ll +++ b/test/Transforms/InstCombine/select.ll @@ -997,111 +997,6 @@ define <2 x i32> @select_icmp_eq_and_1_0_or_vector_of_2s(i32 %x, <2 x i32> %y) { ret <2 x i32> %select } -; CHECK-LABEL: @select_icmp_and_8_eq_0_or_8( -; CHECK-NEXT: [[OR:%[a-z0-9]+]] = or i32 %x, 8 -; CHECK-NEXT: ret i32 [[OR]] -define i32 @select_icmp_and_8_eq_0_or_8(i32 %x) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %or = or i32 %x, 8 - %or.x = select i1 %cmp, i32 %or, i32 %x - ret i32 %or.x -} - -; CHECK-LABEL: @select_icmp_and_8_ne_0_xor_8( -; CHECK-NEXT: [[AND:%[a-z0-9]+]] = and i32 %x, -9 -; CHECK-NEXT: ret i32 [[AND]] -define i32 @select_icmp_and_8_ne_0_xor_8(i32 %x) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %xor = xor i32 %x, 8 - %x.xor = select i1 %cmp, i32 %x, i32 %xor - ret i32 %x.xor -} - -; CHECK-LABEL: @select_icmp_and_8_eq_0_xor_8( -; CHECK-NEXT: [[OR:%[a-z0-9]+]] = or i32 %x, 8 -; CHECK-NEXT: ret i32 [[OR]] -define i32 @select_icmp_and_8_eq_0_xor_8(i32 %x) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %xor = xor i32 %x, 8 - %xor.x = select i1 %cmp, i32 %xor, i32 %x - ret i32 %xor.x -} - -; CHECK-LABEL: @select_icmp_and_8_ne_0_and_not_8( -; CHECK-NEXT: [[AND:%[a-z0-9]+]] = and i32 %x, -9 -; CHECK-NEXT: ret i32 [[AND]] -define i32 @select_icmp_and_8_ne_0_and_not_8(i32 %x) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %and1 = and i32 %x, -9 - %x.and1 = select i1 %cmp, i32 %x, i32 %and1 - ret i32 %x.and1 -} - -; CHECK-LABEL: @select_icmp_and_8_eq_0_and_not_8( -; CHECK-NEXT: ret i32 %x -define i32 @select_icmp_and_8_eq_0_and_not_8(i32 %x) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %and1 = and i32 %x, -9 - %and1.x = select i1 %cmp, i32 %and1, i32 %x - ret i32 %and1.x -} - -; CHECK-LABEL: @select_icmp_x_and_8_eq_0_y_xor_8( -; CHECK: select i1 %cmp, i64 %y, i64 %xor -define i64 @select_icmp_x_and_8_eq_0_y_xor_8(i32 %x, i64 %y) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %xor = xor i64 %y, 8 - %y.xor = select i1 %cmp, i64 %y, i64 %xor - ret i64 %y.xor -} - -; CHECK-LABEL: @select_icmp_x_and_8_eq_0_y_and_not_8( -; CHECK: select i1 %cmp, i64 %y, i64 %and1 -define i64 @select_icmp_x_and_8_eq_0_y_and_not_8(i32 %x, i64 %y) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %and1 = and i64 %y, -9 - %y.and1 = select i1 %cmp, i64 %y, i64 %and1 - ret i64 %y.and1 -} - -; CHECK-LABEL: @select_icmp_x_and_8_ne_0_y_xor_8( -; CHECK: select i1 %cmp, i64 %xor, i64 %y -define i64 @select_icmp_x_and_8_ne_0_y_xor_8(i32 %x, i64 %y) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %xor = xor i64 %y, 8 - %xor.y = select i1 %cmp, i64 %xor, i64 %y - ret i64 %xor.y -} - -; CHECK-LABEL: @select_icmp_x_and_8_ne_0_y_and_not_8( -; CHECK: select i1 %cmp, i64 %and1, i64 %y -define i64 @select_icmp_x_and_8_ne_0_y_and_not_8(i32 %x, i64 %y) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %and1 = and i64 %y, -9 - %and1.y = select i1 %cmp, i64 %and1, i64 %y - ret i64 %and1.y -} - -; CHECK-LABEL: @select_icmp_x_and_8_ne_0_y_or_8( -; CHECK: xor i64 %1, 8 -; CHECK: or i64 %2, %y -define i64 @select_icmp_x_and_8_ne_0_y_or_8(i32 %x, i64 %y) { - %and = and i32 %x, 8 - %cmp = icmp eq i32 %and, 0 - %or = or i64 %y, 8 - %or.y = select i1 %cmp, i64 %or, i64 %y - ret i64 %or.y -} - define i32 @test65(i64 %x) { %1 = and i64 %x, 16 %2 = icmp ne i64 %1, 0 @@ -1491,3 +1386,13 @@ entry: %v = load i128* %p ret i128 %v } + +define i32 @test87(i32 %x) { + %and = and i32 %x, 1 + %cmp = icmp ne i32 %and, 0 + %and1 = and i32 %x, -2 + %and1.x = select i1 %cmp, i32 %and1, i32 %x + ret i32 %and1.x +; CHECK-LABEL: @test87( +; CHECK: and i32 %x, -2 +}