[IndVars] Add test for #82243.

Test for #82243.

Author: fhahn

llvm/test/Transforms/IndVarSimplify/hoist-wide-inc-for-narrow-use-recompute-flags.ll

@@ -0,0 +1,58 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -p indvars -S %s | FileCheck %s
+
+target datalayout = "e-m:o-i64:64-i128:128-n32:64-S128"
+
+; Test for https://github.com/llvm/llvm-project/issues/82243.
+; FIXME: Currently no-wrap flags on hoisted wide IV are not dropped properly.
+define void @test_pr82243(ptr %f) {
+; CHECK-LABEL: define void @test_pr82243(
+; CHECK-SAME: ptr [[F:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br label [[OUTER_HEADER:%.*]]
+; CHECK:       outer.header:
+; CHECK-NEXT:    [[INDVARS_IV:%.*]] = phi i64 [ [[INDVARS_IV_NEXT:%.*]], [[OUTER_LATCH:%.*]] ], [ 1, [[ENTRY:%.*]] ]
+; CHECK-NEXT:    [[GEP_IV_EXT:%.*]] = getelementptr i32, ptr [[F]], i64 [[INDVARS_IV]]
+; CHECK-NEXT:    store i32 1, ptr [[GEP_IV_EXT]], align 4
+; CHECK-NEXT:    [[INDVARS_IV_NEXT]] = add nuw nsw i64 [[INDVARS_IV]], -1
+; CHECK-NEXT:    [[TMP0:%.*]] = trunc i64 [[INDVARS_IV_NEXT]] to i32
+; CHECK-NEXT:    [[SHL:%.*]] = shl i32 123, [[TMP0]]
+; CHECK-NEXT:    [[GEP_SHL:%.*]] = getelementptr i32, ptr [[F]], i32 [[SHL]]
+; CHECK-NEXT:    br label [[INNER_HEADER:%.*]]
+; CHECK:       inner.header:
+; CHECK-NEXT:    store i32 0, ptr [[GEP_SHL]], align 4
+; CHECK-NEXT:    br i1 false, label [[INNER_LATCH:%.*]], label [[EXIT:%.*]]
+; CHECK:       inner.latch:
+; CHECK-NEXT:    br i1 false, label [[INNER_HEADER]], label [[OUTER_LATCH]]
+; CHECK:       outer.latch:
+; CHECK-NEXT:    br label [[OUTER_HEADER]]
+; CHECK:       exit:
+; CHECK-NEXT:    ret void
+;
+entry:
+  br label %outer.header
+
+outer.header:
+  %iv = phi i32 [ 1, %entry ], [ %iv.next, %outer.latch ]
+  %iv.sext = sext i32 %iv to i64
+  %gep.iv.ext = getelementptr i32, ptr %f, i64 %iv.sext
+  store i32 1, ptr %gep.iv.ext
+  %sub = add i32 %iv, -1
+  %shl = shl i32 123, %sub
+  %gep.shl = getelementptr i32, ptr %f, i32 %shl
+  br label %inner.header
+
+inner.header:
+  store i32 0, ptr %gep.shl, align 4
+  br i1 false, label %inner.latch, label %exit
+
+inner.latch:
+  br i1 false, label %inner.header, label %outer.latch
+
+outer.latch:
+  %iv.next = add i32 %iv, -1
+  br label %outer.header
+
+exit:
+  ret void
+}