[llvm] 223f9b0 - Revert "[SCCP] Constant propagation through freeze instruction"

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2023-06-01T15:30:46+02:00
New Revision: 223f9b096e36cd8e0dd414edd11ce12bf046213b

URL: https://github.com/llvm/llvm-project/commit/223f9b096e36cd8e0dd414edd11ce12bf046213b
DIFF: https://github.com/llvm/llvm-project/commit/223f9b096e36cd8e0dd414edd11ce12bf046213b.diff

LOG: Revert "[SCCP] Constant propagation through freeze instruction"

This reverts commit 559d47a1790e1a9f9b1f8838a443eb7624ef1ac7.

Caused failure on sanitizer-aarch64-linux-bootstrap-ubsan:

    clang++: /b/sanitizer-aarch64-linux-bootstrap-ubsan/build/llvm-project/llvm/lib/Transforms/Utils/SCCPSolver.cpp:442: llvm::ValueLatticeElement &llvm::SCCPInstVisitor::getValueState(llvm::Value *): Assertion `!V->getType()->isStructTy() && "Should use getStructValueState"' failed.

Added: 
    

Modified: 
    llvm/lib/Transforms/Utils/SCCPSolver.cpp
    llvm/test/Transforms/SCCP/freeze.ll

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/Utils/SCCPSolver.cpp b/llvm/lib/Transforms/Utils/SCCPSolver.cpp
index 5e3b721a21755..881c3cc7b56f6 100644
--- a/llvm/lib/Transforms/Utils/SCCPSolver.cpp
+++ b/llvm/lib/Transforms/Utils/SCCPSolver.cpp
@@ -17,7 +17,6 @@
 #include "llvm/Analysis/InstructionSimplify.h"
 #include "llvm/Analysis/ValueLattice.h"
 #include "llvm/Analysis/ValueLatticeUtils.h"
-#include "llvm/Analysis/ValueTracking.h"
 #include "llvm/IR/InstVisitor.h"
 #include "llvm/Support/Casting.h"
 #include "llvm/Support/Debug.h"
@@ -613,7 +612,6 @@ class SCCPInstVisitor : public InstVisitor<SCCPInstVisitor> {
   void visitCastInst(CastInst &I);
   void visitSelectInst(SelectInst &I);
   void visitUnaryOperator(Instruction &I);
-  void visitFreezeInst(FreezeInst &I);
   void visitBinaryOperator(Instruction &I);
   void visitCmpInst(CmpInst &I);
   void visitExtractValueInst(ExtractValueInst &EVI);
@@ -1406,25 +1404,6 @@ void SCCPInstVisitor::visitUnaryOperator(Instruction &I) {
   markOverdefined(&I);
 }
 
-void SCCPInstVisitor::visitFreezeInst(FreezeInst &I) {
-  ValueLatticeElement V0State = getValueState(I.getOperand(0));
-  ValueLatticeElement &IV = ValueState[&I];
-  // resolvedUndefsIn might mark I as overdefined. Bail out, even if we would
-  // discover a concrete value later.
-  if (SCCPSolver::isOverdefined(IV))
-    return (void)markOverdefined(&I);
-
-  // If something is unknown/undef, wait for it to resolve.
-  if (V0State.isUnknownOrUndef())
-    return;
-
-  if (SCCPSolver::isConstant(V0State) &&
-      isGuaranteedNotToBeUndefOrPoison(getConstant(V0State)))
-    return (void)markConstant(IV, &I, getConstant(V0State));
-
-  markOverdefined(&I);
-}
-
 // Handle Binary Operators.
 void SCCPInstVisitor::visitBinaryOperator(Instruction &I) {
   ValueLatticeElement V1State = getValueState(I.getOperand(0));

diff  --git a/llvm/test/Transforms/SCCP/freeze.ll b/llvm/test/Transforms/SCCP/freeze.ll
index 36cec13aaa5dd..b6a2a5628e5e9 100644
--- a/llvm/test/Transforms/SCCP/freeze.ll
+++ b/llvm/test/Transforms/SCCP/freeze.ll
@@ -1,7 +1,6 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -passes=ipsccp -S %s | FileCheck %s
 
- at g = global i64 0
 declare void @use(i1)
 
 define i1 @freeze_undef_i1() {
@@ -40,48 +39,6 @@ define <2 x i32> @freeze_undef_vector() {
   ret <2 x i32> %fr
 }
 
-define i1 @freeze_const_i1() {
-; CHECK-LABEL: @freeze_const_i1(
-; CHECK-NEXT:    ret i1 true
-;
-  %fr = freeze i1 1
-  ret i1 %fr
-}
-
-define ptr @freeze_const_ptr() {
-; CHECK-LABEL: @freeze_const_ptr(
-; CHECK-NEXT:    ret ptr inttoptr (i32 256 to ptr)
-;
-  %fr = freeze ptr inttoptr (i32 256 to ptr)
-  ret ptr %fr
-}
-
-define float @freeze_const_float() {
-; CHECK-LABEL: @freeze_const_float(
-; CHECK-NEXT:    ret float 2.500000e-01
-;
-  %fr = freeze float 2.500000e-01
-  ret float %fr
-}
-
-define <2 x i32> @freeze_const_vector() {
-; CHECK-LABEL: @freeze_const_vector(
-; CHECK-NEXT:    ret <2 x i32> <i32 1, i32 2>
-;
-  %fr = freeze <2 x i32> <i32 1, i32 2>
-  ret <2 x i32> %fr
-}
-
-; make sure we don't constant-propagate values that could potentially be poison
-define i64 @maybe_poison() {
-; CHECK-LABEL: @maybe_poison(
-; CHECK-NEXT:    [[FR:%.*]] = freeze i64 add nuw (i64 ptrtoint (ptr @g to i64), i64 123)
-; CHECK-NEXT:    ret i64 [[FR]]
-;
-  %fr = freeze i64 add nuw (i64 ptrtoint (ptr @g to i64), i64 123)
-  ret i64 %fr
-}
-
 define i1 @propagate_range_from_and_through_freeze(i32 %x, i32 %y) {
 ; CHECK-LABEL: @propagate_range_from_and_through_freeze(
 ; CHECK-NEXT:    [[AND:%.*]] = and i32 [[X:%.*]], 3