Move the complex address expression out of DIVariable and into an extra

argument of the llvm.dbg.declare/llvm.dbg.value intrinsics.

Previously, DIVariable was a variable-length field that has an optional
reference to a Metadata array consisting of a variable number of
complex address expressions. In the case of OpPiece expressions this is
wasting a lot of storage in IR, because when an aggregate type is, e.g.,
SROA'd into all of its n individual members, the IR will contain n copies
of the DIVariable, all alike, only differing in the complex address
reference at the end.

By making the complex address into an extra argument of the
dbg.value/dbg.declare intrinsics, all of the pieces can reference the
same variable and the complex address expressions can be uniqued across
the CU, too.
Down the road, this will allow us to move other flags, such as
"indirection" out of the DIVariable, too.

The new intrinsics look like this:
declare void @llvm.dbg.declare(metadata %storage, metadata %var, metadata %expr)
declare void @llvm.dbg.value(metadata %storage, i64 %offset, metadata %var, metadata %expr)

This patch adds a new LLVM-local tag to DIExpressions, so we can detect
and pretty-print DIExpression metadata nodes.

What this patch doesn't do:

This patch does not touch the "Indirect" field in DIVariable; but moving
that into the expression would be a natural next step.

http://reviews.llvm.org/D4919
rdar://problem/17994491

Thanks to dblaikie and dexonsmith for reviewing this patch!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@218778 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 13 insertions, 13 deletions

diff --git a/test/CodeGen/ARM/debug-info-s16-reg.ll b/test/CodeGen/ARM/debug-info-s16-reg.ll
index 6d992d9a4f5..79fc0575715 100644
--- a/test/CodeGen/ARM/debug-info-s16-reg.ll
+++ b/test/CodeGen/ARM/debug-info-s16-reg.ll
@@ -15,9 +15,9 @@ target triple = "thumbv7-apple-macosx10.6.7"
 
 define i32 @inlineprinter(i8* %ptr, float %val, i8 zeroext %c) nounwind optsize ssp {
 entry:
-  tail call void @llvm.dbg.value(metadata !{i8* %ptr}, i64 0, metadata !8), !dbg !24
-  tail call void @llvm.dbg.value(metadata !{float %val}, i64 0, metadata !10), !dbg !25
-  tail call void @llvm.dbg.value(metadata !{i8 %c}, i64 0, metadata !12), !dbg !26
+  tail call void @llvm.dbg.value(metadata !{i8* %ptr}, i64 0, metadata !8, metadata !{}), !dbg !24
+  tail call void @llvm.dbg.value(metadata !{float %val}, i64 0, metadata !10, metadata !{}), !dbg !25
+  tail call void @llvm.dbg.value(metadata !{i8 %c}, i64 0, metadata !12, metadata !{}), !dbg !26
   %conv = fpext float %val to double, !dbg !27
   %conv3 = zext i8 %c to i32, !dbg !27
   %call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i8* %ptr, double %conv, i32 %conv3) nounwind optsize, !dbg !27
@@ -28,9 +28,9 @@ declare i32 @printf(i8* nocapture, ...) nounwind optsize
 
 define i32 @printer(i8* %ptr, float %val, i8 zeroext %c) nounwind optsize noinline ssp {
 entry:
-  tail call void @llvm.dbg.value(metadata !{i8* %ptr}, i64 0, metadata !14), !dbg !30
-  tail call void @llvm.dbg.value(metadata !{float %val}, i64 0, metadata !15), !dbg !31
-  tail call void @llvm.dbg.value(metadata !{i8 %c}, i64 0, metadata !16), !dbg !32
+  tail call void @llvm.dbg.value(metadata !{i8* %ptr}, i64 0, metadata !14, metadata !{}), !dbg !30
+  tail call void @llvm.dbg.value(metadata !{float %val}, i64 0, metadata !15, metadata !{}), !dbg !31
+  tail call void @llvm.dbg.value(metadata !{i8 %c}, i64 0, metadata !16, metadata !{}), !dbg !32
   %conv = fpext float %val to double, !dbg !33
   %conv3 = zext i8 %c to i32, !dbg !33
   %call = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i8* %ptr, double %conv, i32 %conv3) nounwind optsize, !dbg !33
@@ -39,19 +39,19 @@ entry:
 
 define i32 @main(i32 %argc, i8** nocapture %argv) nounwind optsize ssp {
 entry:
-  tail call void @llvm.dbg.value(metadata !{i32 %argc}, i64 0, metadata !17), !dbg !36
-  tail call void @llvm.dbg.value(metadata !{i8** %argv}, i64 0, metadata !18), !dbg !37
+  tail call void @llvm.dbg.value(metadata !{i32 %argc}, i64 0, metadata !17, metadata !{}), !dbg !36
+  tail call void @llvm.dbg.value(metadata !{i8** %argv}, i64 0, metadata !18, metadata !{}), !dbg !37
   %conv = sitofp i32 %argc to double, !dbg !38
   %add = fadd double %conv, 5.555552e+05, !dbg !38
   %conv1 = fptrunc double %add to float, !dbg !38
-  tail call void @llvm.dbg.value(metadata !{float %conv1}, i64 0, metadata !22), !dbg !38
+  tail call void @llvm.dbg.value(metadata !{float %conv1}, i64 0, metadata !22, metadata !{}), !dbg !38
   %call = tail call i32 @puts(i8* getelementptr inbounds ([6 x i8]* @.str1, i32 0, i32 0)) nounwind optsize, !dbg !39
   %add.ptr = getelementptr i8* bitcast (i32 (i32, i8**)* @main to i8*), i32 %argc, !dbg !40
   %add5 = add nsw i32 %argc, 97, !dbg !40
   %conv6 = trunc i32 %add5 to i8, !dbg !40
-  tail call void @llvm.dbg.value(metadata !{i8* %add.ptr}, i64 0, metadata !8) nounwind, !dbg !41
-  tail call void @llvm.dbg.value(metadata !{float %conv1}, i64 0, metadata !10) nounwind, !dbg !42
-  tail call void @llvm.dbg.value(metadata !{i8 %conv6}, i64 0, metadata !12) nounwind, !dbg !43
+  tail call void @llvm.dbg.value(metadata !{i8* %add.ptr}, i64 0, metadata !8, metadata !{}) nounwind, !dbg !41
+  tail call void @llvm.dbg.value(metadata !{float %conv1}, i64 0, metadata !10, metadata !{}) nounwind, !dbg !42
+  tail call void @llvm.dbg.value(metadata !{i8 %conv6}, i64 0, metadata !12, metadata !{}) nounwind, !dbg !43
   %conv.i = fpext float %conv1 to double, !dbg !44
   %conv3.i = and i32 %add5, 255, !dbg !44
   %call.i = tail call i32 (i8*, ...)* @printf(i8* getelementptr inbounds ([11 x i8]* @.str, i32 0, i32 0), i8* %add.ptr, double %conv.i, i32 %conv3.i) nounwind optsize, !dbg !44
@@ -61,7 +61,7 @@ entry:
 
 declare i32 @puts(i8* nocapture) nounwind optsize
 
-declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnone
 
 !llvm.dbg.cu = !{!2}
 !llvm.module.flags = !{!53}