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[CGP] Fix missing sign extension for base offset in optimizeMemoryInst #161377

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Merged
merged 5 commits into from
Oct 10, 2025
Merged

[CGP] Fix missing sign extension for base offset in optimizeMemoryInst #161377

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926ce13
[CGP] NFC: Add pre-commit test
vladimirradosavljevic Sep 30, 2025
a0ca124
[CGP] Fix missing sign extension for base offset in optimizeMemoryInst
vladimirradosavljevic Sep 30, 2025
57216c7
[CGP] Address comments
vladimirradosavljevic Oct 10, 2025
68cdb30
[CGP] NFC: Add test that exposes another issue
vladimirradosavljevic Oct 10, 2025
9691142
[CGP] Fix issue in one more place
vladimirradosavljevic Oct 10, 2025
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4 changes: 2 additions & 2 deletions llvm/lib/CodeGen/CodeGenPrepare.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -6100,7 +6100,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,

// Add in the Base Offset if present.
if (AddrMode.BaseOffs) {
Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs);
Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs, true);
if (ResultIndex) {
// We need to add this separately from the scale above to help with
// SDAG consecutive load/store merging.
Expand Down Expand Up @@ -6226,7 +6226,7 @@ bool CodeGenPrepare::optimizeMemoryInst(Instruction *MemoryInst, Value *Addr,

// Add in the Base Offset if present.
if (AddrMode.BaseOffs) {
Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs);
Value *V = ConstantInt::get(IntPtrTy, AddrMode.BaseOffs, true);
if (Result)
Result = Builder.CreateAdd(Result, V, "sunkaddr");
else
Expand Down
52 changes: 52 additions & 0 deletions llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll
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@@ -0,0 +1,52 @@
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6
; RUN: opt -S -passes='require<profile-summary>,function(codegenprepare)' < %s | FileCheck --check-prefix=GEP %s
; RUN: opt -S -passes='require<profile-summary>,function(codegenprepare)' -addr-sink-using-gep=false < %s | FileCheck --check-prefix=NO-GEP %s

target triple = "x86_64--linux-gnu"
target datalayout = "e-m:e-p0:128:128-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
; -p0:128:128 is added to ensure that transformation will be triggered.

define i128 @test(i128 %arg) {
; GEP-LABEL: define i128 @test(
; GEP-SAME: i128 [[ARG:%.*]]) {
; GEP-NEXT: [[ENTRY:.*]]:
; GEP-NEXT: [[CMP:%.*]] = icmp ugt i128 [[ARG]], 10
; GEP-NEXT: br i1 [[CMP]], label %[[THEN:.*]], label %[[EXIT:.*]]
; GEP: [[THEN]]:
; GEP-NEXT: [[SUNKADDR:%.*]] = inttoptr i128 [[ARG]] to ptr
; GEP-NEXT: [[SUNKADDR1:%.*]] = getelementptr i8, ptr [[SUNKADDR]], i128 -32
; GEP-NEXT: [[LOAD:%.*]] = load i128, ptr [[SUNKADDR1]], align 16
; GEP-NEXT: br label %[[EXIT]]
; GEP: [[EXIT]]:
; GEP-NEXT: [[PHI:%.*]] = phi i128 [ [[LOAD]], %[[THEN]] ], [ 0, %[[ENTRY]] ]
; GEP-NEXT: ret i128 [[PHI]]
;
; NO-GEP-LABEL: define i128 @test(
; NO-GEP-SAME: i128 [[ARG:%.*]]) {
; NO-GEP-NEXT: [[ENTRY:.*]]:
; NO-GEP-NEXT: [[CMP:%.*]] = icmp ugt i128 [[ARG]], 10
; NO-GEP-NEXT: br i1 [[CMP]], label %[[THEN:.*]], label %[[EXIT:.*]]
; NO-GEP: [[THEN]]:
; NO-GEP-NEXT: [[SUNKADDR:%.*]] = add i128 [[ARG]], -32
; NO-GEP-NEXT: [[SUNKADDR1:%.*]] = inttoptr i128 [[SUNKADDR]] to ptr
; NO-GEP-NEXT: [[LOAD:%.*]] = load i128, ptr [[SUNKADDR1]], align 16
; NO-GEP-NEXT: br label %[[EXIT]]
; NO-GEP: [[EXIT]]:
; NO-GEP-NEXT: [[PHI:%.*]] = phi i128 [ [[LOAD]], %[[THEN]] ], [ 0, %[[ENTRY]] ]
; NO-GEP-NEXT: ret i128 [[PHI]]
;
entry:
%add = add i128 %arg, -32
%cmp = icmp ugt i128 %arg, 10
br i1 %cmp, label %then, label %exit

then:
%inttoptr = inttoptr i128 %add to ptr
%load = load i128, ptr %inttoptr, align 16
br label %exit

exit:
%phi = phi i128 [ %load, %then ], [ 0, %entry ]
ret i128 %phi
}