[llvm] [CodeGen][X86] Fix lowering of tailcalls when `-ms-hotpatch` is used (PR #77245)

[Shengchen Kan via llvm-commits]

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@@ -0,0 +1,69 @@
+; RUN: llc -verify-machineinstrs < %s | FileCheck %s --check-prefix=CHECK
+
+; CHECK: "?mi_new_test@@YAPEAX_K at Z":
+; CHECK-NEXT: # %bb.0:
+; CHECK-NEXT: jmp     mi_new
+
+; CHECK: "?builtin_malloc_test@@YAPEAX_K at Z":
+; CHECK-NEXT: # %bb.0:
+; CHECK-NEXT: jmp     malloc
+
+; // Built with: clang-cl.exe /c patchable-prologue-tailcall.cpp /O2 /hotpatch -Xclang -emit-llvm
+;
+; typedef unsigned long long size_t;
+; 
+; extern "C" {
+;     void* mi_new(size_t size);
+;  }
+;
+; void *mi_new_test(size_t count)
+; {
+;     return mi_new(count);
+; }
+; 
+; void *builtin_malloc_test(size_t count)
+; {
+;     return __builtin_malloc(count);
+; }
+
+; ModuleID = 'patchable-prologue-tailcall.cpp'
+source_filename = "patchable-prologue-tailcall.cpp"
+target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.38.33133"
+
+; Function Attrs: mustprogress nounwind sspstrong uwtable
+define dso_local noundef ptr @"?mi_new_test@@YAPEAX_K at Z"(i64 noundef %count) local_unnamed_addr #0 {
+entry:
+  %call = tail call ptr @mi_new(i64 noundef %count) #4
+  ret ptr %call
+}
+
+declare dso_local ptr @mi_new(i64 noundef) local_unnamed_addr #1
+
+; Function Attrs: mustprogress nofree nounwind sspstrong willreturn memory(inaccessiblemem: readwrite) uwtable
+define dso_local noalias noundef ptr @"?builtin_malloc_test@@YAPEAX_K at Z"(i64 noundef %count) local_unnamed_addr #2 {
+entry:
+  %call = tail call ptr @malloc(i64 noundef %count) #4
+  ret ptr %call
+}
+
+; Function Attrs: mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite)
+declare dso_local noalias noundef ptr @malloc(i64 noundef) local_unnamed_addr #3
+
+attributes #0 = { mustprogress nounwind sspstrong uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "patchable-function"="prologue-short-redirect" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #2 = { mustprogress nofree nounwind sspstrong willreturn memory(inaccessiblemem: readwrite) uwtable "min-legal-vector-width"="0" "no-trapping-math"="true" "patchable-function"="prologue-short-redirect" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #3 = { mustprogress nofree nounwind willreturn allockind("alloc,uninitialized") allocsize(0) memory(inaccessiblemem: readwrite) "alloc-family"="malloc" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cmov,+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
----------------
KanRobert wrote:

Keep the attribute `"patchable-function"="prologue-short-redirect"` only?

https://github.com/llvm/llvm-project/pull/77245