[clang] [llvm] [ARM] musttail fixes (PR #102896)

[Eli Friedman via cfe-commits]

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@@ -0,0 +1,43 @@
+; RUN: llc -mtriple=arm-eabi %s -o - | FileCheck %s
+
+; The repro example from https://github.com/llvm/llvm-project/issues/57069#issuecomment-1212754850
+; Function Attrs: mustprogress nofree noinline norecurse nosync nounwind sspstrong willreturn memory(none)
+define hidden noundef i32 @many_args_callee(i32 noundef %0, i32 noundef %1, i32 noundef %2, i32 noundef %3, i32 noundef %4, i32 noundef %5) local_unnamed_addr #0 {
+  %7 = add nsw i32 %1, %0
+  %8 = add nsw i32 %7, %2
+  %9 = add nsw i32 %8, %3
+  %10 = add nsw i32 %9, %4
+  %11 = add nsw i32 %10, %5
+  ret i32 %11
+}
+
+; Function Attrs: mustprogress nofree norecurse nosync nounwind sspstrong willreturn memory(none)
+define hidden noundef i32 @many_args(i32 noundef %0, i32 noundef %1, i32 noundef %2, i32 noundef %3, i32 noundef %4, i32 noundef %5) local_unnamed_addr #1 {
+; CHECK: 	b	many_args_callee
+  %7 = musttail call noundef i32 @many_args_callee(i32 noundef 1, i32 noundef 2, i32 noundef 3, i32 noundef 4, i32 noundef 5, i32 noundef 6)
+  ret i32 %7
+}
+
+; Test with sret
+; Function Attrs: optsize
+declare dso_local void @sret_callee(ptr dead_on_unwind writable sret({ double, double }) align 8, i16 noundef signext) local_unnamed_addr #1
+
+; Function Attrs: mustprogress optsize
+define dso_local void @sret_caller(ptr dead_on_unwind noalias writable sret({ double, double }) align 8 %agg.result, i16 noundef signext %P0) local_unnamed_addr #0 {
+entry:
+; CHECK: 	b	sret_callee
+  musttail call void @sret_callee(ptr dead_on_unwind writable sret({ double, double }) align 8 %agg.result, i16 noundef signext 20391) #2
+  ret void
+}
+
+%struct.Large = type { [60 x i32] }
+
+; Function Attrs: mustprogress noinline optnone
+define dso_local void @large_caller(i64 noundef %0, i64 noundef %1, %struct.Large* noundef byval(%struct.Large) align 4 %2, %struct.Large* noundef byval(%struct.Large) align 4 %3) #0 {
+entry:
+; CHECK: 	b	large_callee
+  musttail call void @large_callee(i64 noundef %0, i64 noundef %1, %struct.Large* noundef byval(%struct.Large) align 4 %2, %struct.Large* noundef byval(%struct.Large) align 4 %3)
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efriedma-quic wrote:

Please add tests for both "%0, %1, %2, %3" and "%0, %1, %3, %2".

https://github.com/llvm/llvm-project/pull/102896