[llvm] [RISCV][TypePromotion] Dont generate truncs if PromotedType is greater than Source Type (PR #86941)

[Yingwei Zheng via llvm-commits]

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@@ -0,0 +1,27 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -mtriple=riscv64 -passes=typepromotion -S %s | FileCheck %s
+
+; Test that this does not crash
+define i16 @test(i8 %a, i32 %b) {
+; CHECK-LABEL: define i16 @test(
+; CHECK-SAME: i8 [[A:%.*]], i32 [[B:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[TMP0:%.*]] = zext i8 [[A]] to i32
+; CHECK-NEXT:    [[CONV31_I1161_I:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    [[TMP1:%.*]] = zext i16 [[CONV31_I1161_I]] to i64
+; CHECK-NEXT:    [[CMP_I_I_I1163_I:%.*]] = icmp eq i64 [[TMP1]], 0
+; CHECK-NEXT:    [[TMP5:%.*]] = and i32 [[TMP0]], 255
+; CHECK-NEXT:    [[TMP3:%.*]] = zext i32 [[TMP5]] to i64
+; CHECK-NEXT:    [[TMP4:%.*]] = xor i64 [[TMP3]], [[TMP1]]
+; CHECK-NEXT:    [[TMP2:%.*]] = trunc i64 [[TMP4]] to i16
+; CHECK-NEXT:    ret i16 [[TMP2]]
+;
+entry:
+  %0 = zext i8 %a to i32
+  %conv31.i1161.i = trunc i32 %b to i16
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dtcxzyw wrote:

Can you simplify these value names?


https://github.com/llvm/llvm-project/pull/86941