[llvm] [RISCV] Check for legal type before calling getSimpleValueType() in matchSplatAsGather. (PR #157188)

[via llvm-commits]

llvmbot wrote:


<!--LLVM PR SUMMARY COMMENT-->

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

Author: Craig Topper (topperc)

<details>
<summary>Changes</summary>

This just reorders existing so we do the legal type check first.

In this particular test case we're also protected by the i1 check that I also moved earlier.

Fixes #<!-- -->157177.

---
Full diff: https://github.com/llvm/llvm-project/pull/157188.diff


2 Files Affected:

- (modified) llvm/lib/Target/RISCV/RISCVISelLowering.cpp (+4-2) 
- (added) llvm/test/CodeGen/RISCV/rvv/pr157177.ll (+20) 


``````````diff
diff --git a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
index 44434ff51288f..a27bd418a6b01 100644
--- a/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
+++ b/llvm/lib/Target/RISCV/RISCVISelLowering.cpp
@@ -3744,9 +3744,11 @@ static SDValue matchSplatAsGather(SDValue SplatVal, MVT VT, const SDLoc &DL,
   // different
   // FIXME: Support i1 vectors, maybe by promoting to i8?
   MVT EltTy = VT.getVectorElementType();
+  if (EltTy == MVT::i1 ||
+      !DAG.getTargetLoweringInfo().isTypeLegal(Src.getValueType()))
+    return SDValue();
   MVT SrcVT = Src.getSimpleValueType();
-  if (EltTy == MVT::i1 || EltTy != SrcVT.getVectorElementType() ||
-      !DAG.getTargetLoweringInfo().isTypeLegal(SrcVT))
+  if (EltTy != SrcVT.getVectorElementType())
     return SDValue();
   SDValue Idx = SplatVal.getOperand(1);
   // The index must be a legal type.
diff --git a/llvm/test/CodeGen/RISCV/rvv/pr157177.ll b/llvm/test/CodeGen/RISCV/rvv/pr157177.ll
new file mode 100644
index 0000000000000..adf857f833a47
--- /dev/null
+++ b/llvm/test/CodeGen/RISCV/rvv/pr157177.ll
@@ -0,0 +1,20 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; RUN: llc < %s -mtriple=riscv64 -mattr=+v | FileCheck %s
+
+define <vscale x 8 x i1> @main(<120 x i1> %0) #0 {
+; CHECK-LABEL: main:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    li a0, 128
+; CHECK-NEXT:    vsetvli zero, a0, e8, m8, ta, ma
+; CHECK-NEXT:    vfirst.m a0, v0
+; CHECK-NEXT:    seqz a0, a0
+; CHECK-NEXT:    vsetvli a1, zero, e8, m1, ta, ma
+; CHECK-NEXT:    vmv.v.x v8, a0
+; CHECK-NEXT:    vmsne.vi v0, v8, 0
+; CHECK-NEXT:    ret
+entry:
+  %1 = extractelement <120 x i1> %0, i64 0
+  %2 = insertelement <vscale x 8 x i1> zeroinitializer, i1 %1, i64 0
+  %3 = shufflevector <vscale x 8 x i1> %2, <vscale x 8 x i1> zeroinitializer, <vscale x 8 x i32> zeroinitializer
+  ret <vscale x 8 x i1> %3
+}

``````````

</details>


https://github.com/llvm/llvm-project/pull/157188