[llvm] r362449 - [SCCP] Add UnaryOperator visitor to SCCP for unary FNeg
Cameron McInally via llvm-commits
llvm-commits at lists.llvm.org
Mon Jun 3 14:53:56 PDT 2019
Author: mcinally
Date: Mon Jun 3 14:53:56 2019
New Revision: 362449
URL: http://llvm.org/viewvc/llvm-project?rev=362449&view=rev
Log:
[SCCP] Add UnaryOperator visitor to SCCP for unary FNeg
Differential Revision: https://reviews.llvm.org/D62819
Added:
llvm/trunk/test/Transforms/SCCP/apfloat-basictest.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
llvm/trunk/test/Transforms/SCCP/undef-resolve.ll
Modified: llvm/trunk/lib/Transforms/Scalar/SCCP.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/SCCP.cpp?rev=362449&r1=362448&r2=362449&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/SCCP.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/SCCP.cpp Mon Jun 3 14:53:56 2019
@@ -613,6 +613,7 @@ private:
void visitCastInst(CastInst &I);
void visitSelectInst(SelectInst &I);
+ void visitUnaryOperator(Instruction &I);
void visitBinaryOperator(Instruction &I);
void visitCmpInst(CmpInst &I);
void visitExtractValueInst(ExtractValueInst &EVI);
@@ -969,6 +970,29 @@ void SCCPSolver::visitSelectInst(SelectI
markOverdefined(&I);
}
+// Handle Unary Operators.
+void SCCPSolver::visitUnaryOperator(Instruction &I) {
+ LatticeVal V0State = getValueState(I.getOperand(0));
+
+ LatticeVal &IV = ValueState[&I];
+ if (IV.isOverdefined()) return;
+
+ if (V0State.isConstant()) {
+ Constant *C = ConstantExpr::get(I.getOpcode(), V0State.getConstant());
+
+ // op Y -> undef.
+ if (isa<UndefValue>(C))
+ return;
+ return (void)markConstant(IV, &I, C);
+ }
+
+ // If something is undef, wait for it to resolve.
+ if (!V0State.isOverdefined())
+ return;
+
+ markOverdefined(&I);
+}
+
// Handle Binary Operators.
void SCCPSolver::visitBinaryOperator(Instruction &I) {
LatticeVal V1State = getValueState(I.getOperand(0));
@@ -1484,6 +1508,8 @@ bool SCCPSolver::ResolvedUndefsIn(Functi
else
markOverdefined(&I);
return true;
+ case Instruction::FNeg:
+ break; // fneg undef -> undef
case Instruction::ZExt:
case Instruction::SExt:
case Instruction::FPToUI:
Added: llvm/trunk/test/Transforms/SCCP/apfloat-basictest.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SCCP/apfloat-basictest.ll?rev=362449&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SCCP/apfloat-basictest.ll (added)
+++ llvm/trunk/test/Transforms/SCCP/apfloat-basictest.ll Mon Jun 3 14:53:56 2019
@@ -0,0 +1,33 @@
+; This is a basic sanity check for constant propagation. The fneg instruction
+; should be eliminated.
+
+; RUN: opt < %s -sccp -S | FileCheck %s
+
+define double @test(i1 %B) {
+ br i1 %B, label %BB1, label %BB2
+BB1:
+ %Val = fneg double 42.0
+ br label %BB3
+BB2:
+ br label %BB3
+BB3:
+ %Ret = phi double [%Val, %BB1], [1.0, %BB2]
+ ret double %Ret
+; CHECK-LABEL: @test(
+; CHECK: [[PHI:%.*]] = phi double [ -4.200000e+01, %BB1 ], [ 1.000000e+00, %BB2 ]
+}
+
+define double @test1(i1 %B) {
+ br i1 %B, label %BB1, label %BB2
+BB1:
+ %Div = fdiv double 1.0, 1.0
+ %Val = fneg double %Div
+ br label %BB3
+BB2:
+ br label %BB3
+BB3:
+ %Ret = phi double [%Val, %BB1], [1.0, %BB2]
+ ret double %Ret
+; CHECK-LABEL: @test1(
+; CHECK: [[PHI:%.*]] = phi double [ -1.000000e+00, %BB1 ], [ 1.000000e+00, %BB2 ]
+}
Modified: llvm/trunk/test/Transforms/SCCP/undef-resolve.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SCCP/undef-resolve.ll?rev=362449&r1=362448&r2=362449&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/SCCP/undef-resolve.ll (original)
+++ llvm/trunk/test/Transforms/SCCP/undef-resolve.ll Mon Jun 3 14:53:56 2019
@@ -180,3 +180,11 @@ entry:
; CHECK-LABEL: @test11(
; CHECK: ret i32 0
}
+
+; Test unary ops
+define double @test12(double %x) {
+ %t = fneg double undef
+ ret double %t
+; CHECK-LABEL: @test12(
+; CHECK: double undef
+}
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