From 926ce13aec9005dc616e27d1a8bee7ac8bb6d854 Mon Sep 17 00:00:00 2001 From: Vladimir Radosavljevic Date: Tue, 30 Sep 2025 15:25:58 +0200 Subject: [PATCH 1/5] [CGP] NFC: Add pre-commit test --- .../CodeGenPrepare/X86/baseoffs-sext-bug.ll | 52 +++++++++++++++++++ 1 file changed, 52 insertions(+) create mode 100644 llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll new file mode 100644 index 0000000000000..1ceeb492bdb03 --- /dev/null +++ b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll @@ -0,0 +1,52 @@ +; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 6 +; RUN: opt -S -passes='require,function(codegenprepare)' < %s | FileCheck --check-prefix=GEP %s +; RUN: opt -S -passes='require,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 18446744073709551584 +; 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]], 18446744073709551584 +; 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 +} + From a0ca124e457e18a9db3806b4a1cf0ccf68273439 Mon Sep 17 00:00:00 2001 From: Vladimir Radosavljevic Date: Tue, 30 Sep 2025 15:27:36 +0200 Subject: [PATCH 2/5] [CGP] Fix missing sign extension for base offset in optimizeMemoryInst If we have integers larger than 64-bit we need to explicitly sign extend them, otherwise we will get wrong zero extended values. --- llvm/lib/CodeGen/CodeGenPrepare.cpp | 4 ++-- llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll | 4 ++-- 2 files changed, 4 insertions(+), 4 deletions(-) diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index eb73d01b3558c..1a68577652f52 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -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. @@ -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 diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll index 1ceeb492bdb03..a8ef80b389dac 100644 --- a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll +++ b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll @@ -14,7 +14,7 @@ define i128 @test(i128 %arg) { ; 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 18446744073709551584 +; 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]]: @@ -27,7 +27,7 @@ define i128 @test(i128 %arg) { ; 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]], 18446744073709551584 +; 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]] From 57216c7b10036f4cc1521dcc744aab0a30ec9381 Mon Sep 17 00:00:00 2001 From: Vladimir Radosavljevic Date: Fri, 10 Oct 2025 12:04:07 +0200 Subject: [PATCH 3/5] [CGP] Address comments --- llvm/lib/CodeGen/CodeGenPrepare.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index 1a68577652f52..417917656a4bb 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -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, true); + Value *V = ConstantInt::getSigned(IntPtrTy, AddrMode.BaseOffs); if (ResultIndex) { // We need to add this separately from the scale above to help with // SDAG consecutive load/store merging. @@ -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, true); + Value *V = ConstantInt::getSigned(IntPtrTy, AddrMode.BaseOffs); if (Result) Result = Builder.CreateAdd(Result, V, "sunkaddr"); else From 68cdb30604eafe981597a3b52a0df3845b004520 Mon Sep 17 00:00:00 2001 From: Vladimir Radosavljevic Date: Fri, 10 Oct 2025 12:07:48 +0200 Subject: [PATCH 4/5] [CGP] NFC: Add test that exposes another issue --- .../CodeGenPrepare/X86/baseoffs-sext-bug.ll | 29 +++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll index a8ef80b389dac..cf09845737f4b 100644 --- a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll +++ b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll @@ -50,3 +50,32 @@ exit: ret i128 %phi } +define void @test_combine(ptr %ptr, i128 %arg) { +; GEP-LABEL: define void @test_combine( +; GEP-SAME: ptr [[PTR:%.*]], i128 [[ARG:%.*]]) { +; GEP-NEXT: [[ENTRY:.*:]] +; GEP-NEXT: [[CMP:%.*]] = icmp ugt i128 [[ARG]], 10 +; GEP-NEXT: [[SELECT1:%.*]] = select i1 [[CMP]], i128 18446744073709551584, i128 0 +; GEP-NEXT: [[SUNKADDR:%.*]] = getelementptr inbounds i8, ptr [[PTR]], i128 [[SELECT1]] +; GEP-NEXT: store i128 1, ptr [[SUNKADDR]], align 16 +; GEP-NEXT: ret void +; +; NO-GEP-LABEL: define void @test_combine( +; NO-GEP-SAME: ptr [[PTR:%.*]], i128 [[ARG:%.*]]) { +; NO-GEP-NEXT: [[ENTRY:.*:]] +; NO-GEP-NEXT: [[CMP:%.*]] = icmp ugt i128 [[ARG]], 10 +; NO-GEP-NEXT: [[SELECT1:%.*]] = select i1 [[CMP]], i128 18446744073709551584, i128 0 +; NO-GEP-NEXT: [[SUNKADDR:%.*]] = ptrtoint ptr [[PTR]] to i128 +; NO-GEP-NEXT: [[SUNKADDR2:%.*]] = add i128 [[SUNKADDR]], [[SELECT1]] +; NO-GEP-NEXT: [[SUNKADDR3:%.*]] = inttoptr i128 [[SUNKADDR2]] to ptr +; NO-GEP-NEXT: store i128 1, ptr [[SUNKADDR3]], align 16 +; NO-GEP-NEXT: ret void +; +entry: + %cmp = icmp ugt i128 %arg, 10 + %gep = getelementptr inbounds i8, ptr %ptr, i128 -32 + %select = select i1 %cmp, ptr %gep, ptr %ptr + store i128 1, ptr %select, align 16 + ret void +} + From 9691142d3e1d0446a70d5859ad5b529a1ed4134f Mon Sep 17 00:00:00 2001 From: Vladimir Radosavljevic Date: Fri, 10 Oct 2025 12:09:47 +0200 Subject: [PATCH 5/5] [CGP] Fix issue in one more place --- llvm/lib/CodeGen/CodeGenPrepare.cpp | 2 +- llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-) diff --git a/llvm/lib/CodeGen/CodeGenPrepare.cpp b/llvm/lib/CodeGen/CodeGenPrepare.cpp index 417917656a4bb..4320b1d7b1dc6 100644 --- a/llvm/lib/CodeGen/CodeGenPrepare.cpp +++ b/llvm/lib/CodeGen/CodeGenPrepare.cpp @@ -3194,7 +3194,7 @@ struct ExtAddrMode : public TargetLowering::AddrMode { case ScaledRegField: return ScaledReg; case BaseOffsField: - return ConstantInt::get(IntPtrTy, BaseOffs); + return ConstantInt::getSigned(IntPtrTy, BaseOffs); } } diff --git a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll index cf09845737f4b..51a461e61d886 100644 --- a/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll +++ b/llvm/test/Transforms/CodeGenPrepare/X86/baseoffs-sext-bug.ll @@ -55,7 +55,7 @@ define void @test_combine(ptr %ptr, i128 %arg) { ; GEP-SAME: ptr [[PTR:%.*]], i128 [[ARG:%.*]]) { ; GEP-NEXT: [[ENTRY:.*:]] ; GEP-NEXT: [[CMP:%.*]] = icmp ugt i128 [[ARG]], 10 -; GEP-NEXT: [[SELECT1:%.*]] = select i1 [[CMP]], i128 18446744073709551584, i128 0 +; GEP-NEXT: [[SELECT1:%.*]] = select i1 [[CMP]], i128 -32, i128 0 ; GEP-NEXT: [[SUNKADDR:%.*]] = getelementptr inbounds i8, ptr [[PTR]], i128 [[SELECT1]] ; GEP-NEXT: store i128 1, ptr [[SUNKADDR]], align 16 ; GEP-NEXT: ret void @@ -64,7 +64,7 @@ define void @test_combine(ptr %ptr, i128 %arg) { ; NO-GEP-SAME: ptr [[PTR:%.*]], i128 [[ARG:%.*]]) { ; NO-GEP-NEXT: [[ENTRY:.*:]] ; NO-GEP-NEXT: [[CMP:%.*]] = icmp ugt i128 [[ARG]], 10 -; NO-GEP-NEXT: [[SELECT1:%.*]] = select i1 [[CMP]], i128 18446744073709551584, i128 0 +; NO-GEP-NEXT: [[SELECT1:%.*]] = select i1 [[CMP]], i128 -32, i128 0 ; NO-GEP-NEXT: [[SUNKADDR:%.*]] = ptrtoint ptr [[PTR]] to i128 ; NO-GEP-NEXT: [[SUNKADDR2:%.*]] = add i128 [[SUNKADDR]], [[SELECT1]] ; NO-GEP-NEXT: [[SUNKADDR3:%.*]] = inttoptr i128 [[SUNKADDR2]] to ptr