[llvm] edb0708 - [InstCombine] Implement `fcmp (fadd x, 0.0), y` => `fcmp x, y` optimization (#88476)
via llvm-commits
llvm-commits at lists.llvm.org
Mon Apr 15 22:05:34 PDT 2024
Author: Vlad Mishel
Date: 2024-04-16T13:05:29+08:00
New Revision: edb0708dc1ceeaeb3356311a4ddf72a0dc9b224f
URL: https://github.com/llvm/llvm-project/commit/edb0708dc1ceeaeb3356311a4ddf72a0dc9b224f
DIFF: https://github.com/llvm/llvm-project/commit/edb0708dc1ceeaeb3356311a4ddf72a0dc9b224f.diff
LOG: [InstCombine] Implement `fcmp (fadd x, 0.0), y` => `fcmp x, y` optimization (#88476)
This PR addresses issue #88168. It implements an optimization for
the case of
```
define i1 @fcmp_fadd_zero_ugt(float %x, float %y) {
%add = fadd float %x, 0.000000e+00
%cmp = fcmp ugt float %add, %y
ret i1 %cmp
}
```
`=>`
```
define i1 @fcmp_fadd_zero_ugt(float %x, float %y) {
%cmp = fcmp ugt float %x, %y
ret i1 %cmp
}
```
and all other types of `fcmp` instructions (`uge`, `ogt`, etc).
Proofs:
`fadd x, 0.0` https://alive2.llvm.org/ce/z/7FzNnM
`fsub x, 0.0` https://alive2.llvm.org/ce/z/puUxLK
Added:
Modified:
llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
llvm/test/Transforms/InstCombine/fcmp.ll
Removed:
################################################################################
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
index 90550cdbdf8911..ee783eed190a7c 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineCompares.cpp
@@ -8097,6 +8097,14 @@ Instruction *InstCombinerImpl::visitFCmpInst(FCmpInst &I) {
return new FCmpInst(I.getSwappedPredicate(), X, NegC, "", &I);
}
+ // fcmp (fadd X, 0.0), Y --> fcmp X, Y
+ if (match(Op0, m_FAdd(m_Value(X), m_AnyZeroFP())))
+ return new FCmpInst(Pred, X, Op1, "", &I);
+
+ // fcmp X, (fadd Y, 0.0) --> fcmp X, Y
+ if (match(Op1, m_FAdd(m_Value(Y), m_AnyZeroFP())))
+ return new FCmpInst(Pred, Op0, Y, "", &I);
+
if (match(Op0, m_FPExt(m_Value(X)))) {
// fcmp (fpext X), (fpext Y) -> fcmp X, Y
if (match(Op1, m_FPExt(m_Value(Y))) && X->getType() == Y->getType())
diff --git a/llvm/test/Transforms/InstCombine/fcmp.ll b/llvm/test/Transforms/InstCombine/fcmp.ll
index f2701d16d0f3d1..069512b0f2d8eb 100644
--- a/llvm/test/Transforms/InstCombine/fcmp.ll
+++ b/llvm/test/Transforms/InstCombine/fcmp.ll
@@ -1284,3 +1284,205 @@ define <1 x i1> @bitcast_1vec_eq0(i32 %x) {
%cmp = fcmp oeq <1 x float> %f, zeroinitializer
ret <1 x i1> %cmp
}
+
+; Simplify fcmp (x + 0.0), y => fcmp x, y
+
+define i1 @fcmp_fadd_zero_ugt(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ugt(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ugt float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ugt float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_uge(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_uge(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp uge float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp uge float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_ogt(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ogt(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ogt float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ogt float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_oge(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_oge(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp oge float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp oge float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_ult(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ult(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ult float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ult float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_ule(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ule(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ule float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ule float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_olt(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_olt(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp olt float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp olt float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_ole(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ole(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ole float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ole float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_oeq(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_oeq(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp oeq float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp oeq float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_one(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_one(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp one float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp one float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_ueq(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ueq(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ueq float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ueq float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_une(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_une(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp une float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp une float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_ord(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_ord(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ord float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp ord float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_uno(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_uno(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp uno float [[ADD:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp uno float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_neg_zero(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_neg_zero(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ugt float [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, -0.000000e+00
+ %cmp = fcmp ugt float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_zero_switched(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_switched(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ult float [[Y:%.*]], [[X:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %y, 0.000000e+00
+ %cmp = fcmp ugt float %x, %add
+ ret i1 %cmp
+}
+
+define <2 x i1> @fcmp_fadd_zero_vec(<2 x float> %x, <2 x float> %y) {
+; CHECK-LABEL: @fcmp_fadd_zero_vec(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ugt <2 x float> [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret <2 x i1> [[CMP]]
+;
+ %add = fadd <2 x float> %x, <float 0.0, float -0.0>
+ %cmp = fcmp ugt <2 x float> %add, %y
+ ret <2 x i1> %cmp
+}
+
+define i1 @fcmp_fast_fadd_fast_zero(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fast_fadd_fast_zero(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp fast ugt float [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd fast float %x, 0.000000e+00
+ %cmp = fcmp fast ugt float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fast_fadd_zero(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fast_fadd_zero(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp fast ugt float [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd float %x, 0.000000e+00
+ %cmp = fcmp fast ugt float %add, %y
+ ret i1 %cmp
+}
+
+define i1 @fcmp_fadd_fast_zero(float %x, float %y) {
+; CHECK-LABEL: @fcmp_fadd_fast_zero(
+; CHECK-NEXT: [[CMP:%.*]] = fcmp ugt float [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT: ret i1 [[CMP]]
+;
+ %add = fadd fast float %x, 0.000000e+00
+ %cmp = fcmp ugt float %add, %y
+ ret i1 %cmp
+}
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