[llvm] [DAGCombiner] Mark vectors as not AllAddOne/AllSubOne on type mismatch (PR #92195)

[Craig Topper via llvm-commits]

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@@ -0,0 +1,21 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4
+; RUN: llc -mtriple=riscv64-unknown-linux-gnu < %s | FileCheck %s
+; RUN: llc -mtriple=riscv32-unknown-linux-gnu < %s | FileCheck %s
+
+; Dag-combine used to improperly combine a vector vselect of 0 and 2 into
+; 2 + condition(0/1) because one of the two args was transformed from an i32->i64.
+
+define i16 @foo() {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    li a0, 0
+; CHECK-NEXT:    ret
+entry:
+  %insert.0 = insertelement <4 x i16> zeroinitializer, i16 2, i64 0
+  %all.two = shufflevector <4 x i16> %insert.0, <4 x i16> zeroinitializer, <4 x i32> zeroinitializer
+  %sel.0 = select <4 x i1> <i1 true, i1 false, i1 false, i1 false>, <4 x i16> zeroinitializer, <4 x i16> %all.two
+  %mul.0 = call i16 @llvm.vector.reduce.mul.v4i16(<4 x i16> %sel.0)
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topperc wrote:

Is the reduce needed? Can we hit the error by returning %sel.0?

https://github.com/llvm/llvm-project/pull/92195