[ArgPromotion] Add test case for #84807.

Test case for #84807,
showing a mis-compile in ArgPromotion.

Author: fhahn

llvm/test/Transforms/ArgumentPromotion/aliasing-and-non-aliasing-loads-with-clobber.ll

@@ -0,0 +1,100 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; RUN: opt -p argpromotion -S %s | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+
+@f = dso_local global { i16, i64 } { i16 1, i64 0 }, align 8
+
+; Test case for https://github.com/llvm/llvm-project/issues/84807.
+
+; FIXME: Currently the loads from @callee are moved to @caller, even though
+;        the store in %then may aliases to load from %q.
+
+define i32 @caller1(i1 %c) {
+; CHECK-LABEL: define i32 @caller1(
+; CHECK-SAME: i1 [[C:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    [[F_VAL:%.*]] = load i16, ptr @f, align 8
+; CHECK-NEXT:    [[TMP0:%.*]] = getelementptr i8, ptr @f, i64 8
+; CHECK-NEXT:    [[F_VAL1:%.*]] = load i64, ptr [[TMP0]], align 8
+; CHECK-NEXT:    call void @callee1(i16 [[F_VAL]], i64 [[F_VAL1]], i1 [[C]])
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  call void @callee1(ptr noundef nonnull @f, i1 %c)
+  ret i32 0
+}
+
+define internal void @callee1(ptr nocapture noundef readonly %q, i1 %c) {
+; CHECK-LABEL: define internal void @callee1(
+; CHECK-SAME: i16 [[Q_0_VAL:%.*]], i64 [[Q_8_VAL:%.*]], i1 [[C:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[C]], label [[THEN:%.*]], label [[EXIT:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    store i16 123, ptr @f, align 8
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    call void @use(i16 [[Q_0_VAL]], i64 [[Q_8_VAL]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  br i1 %c, label %then, label %exit
+
+then:
+  store i16 123, ptr @f, align 8
+  br label %exit
+
+exit:
+  %l.0 = load i16, ptr %q, align 8
+  %gep.8  = getelementptr inbounds i8, ptr %q, i64 8
+  %l.1 = load i64, ptr %gep.8, align 8
+  call void @use(i16 %l.0, i64 %l.1)
+  ret void
+
+  uselistorder ptr %q, { 1, 0 }
+}
+
+; Same as @caller1/callee2, but with default uselist order.
+define i32 @caller2(i1 %c) {
+; CHECK-LABEL: define i32 @caller2(
+; CHECK-SAME: i1 [[C:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    call void @callee2(ptr noundef nonnull @f, i1 [[C]])
+; CHECK-NEXT:    ret i32 0
+;
+entry:
+  call void @callee2(ptr noundef nonnull @f, i1 %c)
+  ret i32 0
+}
+
+define internal void @callee2(ptr nocapture noundef readonly %q, i1 %c) {
+; CHECK-LABEL: define internal void @callee2(
+; CHECK-SAME: ptr nocapture noundef readonly [[Q:%.*]], i1 [[C:%.*]]) {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    br i1 [[C]], label [[THEN:%.*]], label [[EXIT:%.*]]
+; CHECK:       then:
+; CHECK-NEXT:    store i16 123, ptr @f, align 8
+; CHECK-NEXT:    br label [[EXIT]]
+; CHECK:       exit:
+; CHECK-NEXT:    [[Q_0_VAL:%.*]] = load i16, ptr [[Q]], align 8
+; CHECK-NEXT:    [[GEP_8:%.*]] = getelementptr inbounds i8, ptr [[Q]], i64 8
+; CHECK-NEXT:    [[Q_8_VAL:%.*]] = load i64, ptr [[GEP_8]], align 8
+; CHECK-NEXT:    call void @use(i16 [[Q_0_VAL]], i64 [[Q_8_VAL]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  br i1 %c, label %then, label %exit
+
+then:
+  store i16 123, ptr @f, align 8
+  br label %exit
+
+exit:
+  %l.0 = load i16, ptr %q, align 8
+  %gep.8  = getelementptr inbounds i8, ptr %q, i64 8
+  %l.1 = load i64, ptr %gep.8, align 8
+  call void @use(i16 %l.0, i64 %l.1)
+  ret void
+}
+
+declare void @use(i16, i64)