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release/20.x: [RISCV] Use getSignedConstant for negative values. (#125903) #125953

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Merged
merged 1 commit into from
Feb 6, 2025

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@llvmbot llvmbot commented Feb 5, 2025

Backport 0d7ee52

Requested by: @topperc

@llvmbot llvmbot added this to the LLVM 20.X Release milestone Feb 5, 2025
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llvmbot commented Feb 5, 2025

@preames What do you think about merging this PR to the release branch?

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llvmbot commented Feb 5, 2025

@llvm/pr-subscribers-backend-risc-v

Author: None (llvmbot)

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Backport 0d7ee52

Requested by: @topperc


Full diff: https://github.com/llvm/llvm-project/pull/125953.diff

3 Files Affected:

  • (modified) llvm/lib/Target/RISCV/RISCVISelLowering.cpp (+2-2)
  • (modified) llvm/test/CodeGen/RISCV/rvv/vp-combine-reverse-load.ll (+1)
  • (modified) llvm/test/CodeGen/RISCV/rvv/vp-combine-store-reverse.ll (+1)
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 8d09e534b1858bc..8b5ee3e67ce637c 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -16297,7 +16297,7 @@ static SDValue performVP_REVERSECombine(SDNode *N, SelectionDAG &DAG,
   SDValue Temp2 = DAG.getNode(ISD::MUL, DL, XLenVT, Temp1,
                               DAG.getConstant(ElemWidthByte, DL, XLenVT));
   SDValue Base = DAG.getNode(ISD::ADD, DL, XLenVT, VPLoad->getBasePtr(), Temp2);
-  SDValue Stride = DAG.getConstant(-ElemWidthByte, DL, XLenVT);
+  SDValue Stride = DAG.getSignedConstant(-ElemWidthByte, DL, XLenVT);
 
   MachineFunction &MF = DAG.getMachineFunction();
   MachinePointerInfo PtrInfo(VPLoad->getAddressSpace());
@@ -16358,7 +16358,7 @@ static SDValue performVP_STORECombine(SDNode *N, SelectionDAG &DAG,
                               DAG.getConstant(ElemWidthByte, DL, XLenVT));
   SDValue Base =
       DAG.getNode(ISD::ADD, DL, XLenVT, VPStore->getBasePtr(), Temp2);
-  SDValue Stride = DAG.getConstant(-ElemWidthByte, DL, XLenVT);
+  SDValue Stride = DAG.getSignedConstant(-ElemWidthByte, DL, XLenVT);
 
   MachineFunction &MF = DAG.getMachineFunction();
   MachinePointerInfo PtrInfo(VPStore->getAddressSpace());
diff --git a/llvm/test/CodeGen/RISCV/rvv/vp-combine-reverse-load.ll b/llvm/test/CodeGen/RISCV/rvv/vp-combine-reverse-load.ll
index 50e26bd14107002..24d8e56fa17febc 100644
--- a/llvm/test/CodeGen/RISCV/rvv/vp-combine-reverse-load.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/vp-combine-reverse-load.ll
@@ -1,4 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -mattr=+f,+v -verify-machineinstrs < %s | FileCheck %s
 ; RUN: llc -mtriple=riscv64 -mattr=+f,+v -verify-machineinstrs < %s | FileCheck %s
 
 define <vscale x 2 x float> @test_reverse_load_combiner(<vscale x 2 x float>* %ptr, i32 zeroext %evl) {
diff --git a/llvm/test/CodeGen/RISCV/rvv/vp-combine-store-reverse.ll b/llvm/test/CodeGen/RISCV/rvv/vp-combine-store-reverse.ll
index 4896a1367935ac3..a2466c48b0ab7d9 100644
--- a/llvm/test/CodeGen/RISCV/rvv/vp-combine-store-reverse.ll
+++ b/llvm/test/CodeGen/RISCV/rvv/vp-combine-store-reverse.ll
@@ -1,4 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=riscv32 -mattr=+f,+v -verify-machineinstrs < %s | FileCheck %s
 ; RUN: llc -mtriple=riscv64 -mattr=+f,+v -verify-machineinstrs < %s | FileCheck %s
 
 define void @test_store_reverse_combiner(<vscale x 2 x float> %val, <vscale x 2 x float>* %ptr, i32 zeroext %evl) {

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LGTM

The APInt constructor asserts if bits are set past the size of the APInt
unless it is signed. This currently fails on RV32 because more than XLen
bits are set.

(cherry picked from commit 0d7ee52)
@tstellar tstellar merged commit c08c9f9 into llvm:release/20.x Feb 6, 2025
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github-actions bot commented Feb 6, 2025

@topperc (or anyone else). If you would like to add a note about this fix in the release notes (completely optional). Please reply to this comment with a one or two sentence description of the fix. When you are done, please add the release:note label to this PR.

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