[framelowering] Skip dbg values when getting next/previous instruction.

Summary:
In mergeSPUpdates, debug values need to be ignored when getting the
previous element, otherwise debug data could have an impact on codegen.

In eliminateCallFramePseudoInstr, debug values after the erased element
could have an impact on codegen and should be skipped.

Closes PR31319 (https://llvm.org/bugs/show_bug.cgi?id=31319)

Reviewers: aprantl, MatzeB, mkuper

Subscribers: gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D27688

llvm-svn: 290955

1 files changed, 33 insertions, 8 deletions

diff --git a/llvm/test/CodeGen/X86/frame-lowering-debug-intrinsic.ll b/llvm/test/CodeGen/X86/frame-lowering-debug-intrinsic.ll
index 8614d1b4c6c..e86d094ac34 100644
--- a/llvm/test/CodeGen/X86/frame-lowering-debug-intrinsic.ll
+++ b/llvm/test/CodeGen/X86/frame-lowering-debug-intrinsic.ll
@@ -2,31 +2,56 @@
 ;
 ; RUN: llc -O1 -mtriple=x86_64-unknown-unknown -o - %s | FileCheck %s
 
-
-define i64 @noDebug(i64 %a) {
+define i64 @fn1NoDebug(i64 %a) {
   %call = call i64 @fn(i64 %a, i64 0)
   ret i64 %call
 }
 
-; CHECK-LABEL: noDebug
+; CHECK-LABEL: fn1NoDebug
 ; CHECK: popq %rcx
-; CHECK: ret
-
+; CHECK-NEXT: ret
 
-define i64 @withDebug(i64 %a) !dbg !4 {
+define i64 @fn1WithDebug(i64 %a) !dbg !4 {
   %call = call i64 @fn(i64 %a, i64 0)
   tail call void @llvm.dbg.value(metadata i64 %call, i64 0, metadata !5, metadata !6), !dbg !7
   ret i64 %call
 }
 
-; CHECK-LABEL: withDebug
+; CHECK-LABEL: fn1WithDebug
 ; CHECK: popq %rcx
-; CHECK: ret
+; CHECK-NEXT: ret
+
+%struct.Buffer = type { i8, [63 x i8] }
+
+define void @fn2NoDebug(%struct.Buffer* byval align 64 %p1) {
+  ret void
+}
+
+; CHECK-LABEL: fn2NoDebug
+; CHECK: and
+; CHECK-NOT: add
+; CHECK-NOT: sub
+; CHECK: mov
+; CHECK-NEXT: pop
+; CHECK-NEXT: ret
+
+define void @fn2WithDebug(%struct.Buffer* byval align 64 %p1) !dbg !4 {
+  call void @llvm.dbg.declare(metadata %struct.Buffer* %p1, metadata !5, metadata !6), !dbg !7
+  ret void
+}
 
+; CHECK-LABEL: fn2WithDebug
+; CHECK: and
+; CHECK-NOT: add
+; CHECK-NOT: sub
+; CHECK: mov
+; CHECK-NEXT: pop
+; CHECK-NEXT: ret
 
 declare i64 @fn(i64, i64)
 
 declare void @llvm.dbg.value(metadata, i64, metadata, metadata)
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
 
 !llvm.dbg.cu = !{!0}
 !llvm.module.flags = !{!2,!3}