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!

Note: I accidentally committed a bogus older version of this patch previously.
llvm-svn: 218787

1 files changed, 18 insertions, 18 deletions

diff --git a/llvm/test/DebugInfo/X86/sret.ll b/llvm/test/DebugInfo/X86/sret.ll
index be425de90e2..af219caae5e 100644
--- a/llvm/test/DebugInfo/X86/sret.ll
+++ b/llvm/test/DebugInfo/X86/sret.ll
@@ -23,9 +23,9 @@ entry:
   %this.addr = alloca %class.A*, align 8
   %i.addr = alloca i32, align 4
   store %class.A* %this, %class.A** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !67), !dbg !69
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !67, metadata !{i32 786690}), !dbg !69
   store i32 %i, i32* %i.addr, align 4
-  call void @llvm.dbg.declare(metadata !{i32* %i.addr}, metadata !70), !dbg !71
+  call void @llvm.dbg.declare(metadata !{i32* %i.addr}, metadata !70, metadata !{i32 786690}), !dbg !71
   %this1 = load %class.A** %this.addr
   %0 = bitcast %class.A* %this1 to i8***, !dbg !72
   store i8** getelementptr inbounds ([4 x i8*]* @_ZTV1A, i64 0, i64 2), i8*** %0, !dbg !72
@@ -36,7 +36,7 @@ entry:
 }
 
 ; Function Attrs: nounwind readnone
-declare void @llvm.dbg.declare(metadata, metadata) #1
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
 
 ; Function Attrs: nounwind uwtable
 define void @_ZN1AC2ERKS_(%class.A* %this, %class.A* %rhs) unnamed_addr #0 align 2 {
@@ -44,9 +44,9 @@ entry:
   %this.addr = alloca %class.A*, align 8
   %rhs.addr = alloca %class.A*, align 8
   store %class.A* %this, %class.A** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !74), !dbg !75
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !74, metadata !{i32 786690}), !dbg !75
   store %class.A* %rhs, %class.A** %rhs.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %rhs.addr}, metadata !76), !dbg !77
+  call void @llvm.dbg.declare(metadata !{%class.A** %rhs.addr}, metadata !76, metadata !{i32 786690}), !dbg !77
   %this1 = load %class.A** %this.addr
   %0 = bitcast %class.A* %this1 to i8***, !dbg !78
   store i8** getelementptr inbounds ([4 x i8*]* @_ZTV1A, i64 0, i64 2), i8*** %0, !dbg !78
@@ -64,9 +64,9 @@ entry:
   %this.addr = alloca %class.A*, align 8
   %rhs.addr = alloca %class.A*, align 8
   store %class.A* %this, %class.A** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !80), !dbg !81
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !80, metadata !{i32 786690}), !dbg !81
   store %class.A* %rhs, %class.A** %rhs.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %rhs.addr}, metadata !82), !dbg !83
+  call void @llvm.dbg.declare(metadata !{%class.A** %rhs.addr}, metadata !82, metadata !{i32 786690}), !dbg !83
   %this1 = load %class.A** %this.addr
   %0 = load %class.A** %rhs.addr, align 8, !dbg !84
   %m_int = getelementptr inbounds %class.A* %0, i32 0, i32 1, !dbg !84
@@ -81,7 +81,7 @@ define i32 @_ZN1A7get_intEv(%class.A* %this) #0 align 2 {
 entry:
   %this.addr = alloca %class.A*, align 8
   store %class.A* %this, %class.A** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !86), !dbg !87
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !86, metadata !{i32 786690}), !dbg !87
   %this1 = load %class.A** %this.addr
   %m_int = getelementptr inbounds %class.A* %this1, i32 0, i32 1, !dbg !88
   %0 = load i32* %m_int, align 4, !dbg !88
@@ -95,10 +95,10 @@ entry:
   %nrvo = alloca i1
   %cleanup.dest.slot = alloca i32
   store %class.B* %this, %class.B** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.B** %this.addr}, metadata !89), !dbg !91
+  call void @llvm.dbg.declare(metadata !{%class.B** %this.addr}, metadata !89, metadata !{i32 786690}), !dbg !91
   %this1 = load %class.B** %this.addr
   store i1 false, i1* %nrvo, !dbg !92
-  call void @llvm.dbg.declare(metadata !{%class.A* %agg.result}, metadata !93), !dbg !92
+  call void @llvm.dbg.declare(metadata !{%class.A* %agg.result}, metadata !93, metadata !{i32 786690}), !dbg !92
   call void @_ZN1AC1Ei(%class.A* %agg.result, i32 12), !dbg !92
   store i1 true, i1* %nrvo, !dbg !94
   store i32 1, i32* %cleanup.dest.slot
@@ -118,7 +118,7 @@ define linkonce_odr void @_ZN1AD2Ev(%class.A* %this) unnamed_addr #0 align 2 {
 entry:
   %this.addr = alloca %class.A*, align 8
   store %class.A* %this, %class.A** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !101), !dbg !102
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !101, metadata !{i32 786690}), !dbg !102
   %this1 = load %class.A** %this.addr
   ret void, !dbg !103
 }
@@ -138,12 +138,12 @@ entry:
   %cleanup.dest.slot = alloca i32
   store i32 0, i32* %retval
   store i32 %argc, i32* %argc.addr, align 4
-  call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !104), !dbg !105
+  call void @llvm.dbg.declare(metadata !{i32* %argc.addr}, metadata !104, metadata !{i32 786690}), !dbg !105
   store i8** %argv, i8*** %argv.addr, align 8
-  call void @llvm.dbg.declare(metadata !{i8*** %argv.addr}, metadata !106), !dbg !105
-  call void @llvm.dbg.declare(metadata !{%class.B* %b}, metadata !107), !dbg !108
+  call void @llvm.dbg.declare(metadata !{i8*** %argv.addr}, metadata !106, metadata !{i32 786690}), !dbg !105
+  call void @llvm.dbg.declare(metadata !{%class.B* %b}, metadata !107, metadata !{i32 786690}), !dbg !108
   call void @_ZN1BC2Ev(%class.B* %b), !dbg !108
-  call void @llvm.dbg.declare(metadata !{i32* %return_val}, metadata !109), !dbg !110
+  call void @llvm.dbg.declare(metadata !{i32* %return_val}, metadata !109, metadata !{i32 786690}), !dbg !110
   call void @_ZN1B9AInstanceEv(%class.A* sret %temp.lvalue, %class.B* %b), !dbg !110
   %call = invoke i32 @_ZN1A7get_intEv(%class.A* %temp.lvalue)
           to label %invoke.cont unwind label %lpad, !dbg !110
@@ -151,7 +151,7 @@ entry:
 invoke.cont:                                      ; preds = %entry
   call void @_ZN1AD2Ev(%class.A* %temp.lvalue), !dbg !111
   store i32 %call, i32* %return_val, align 4, !dbg !111
-  call void @llvm.dbg.declare(metadata !{%class.A* %a}, metadata !113), !dbg !114
+  call void @llvm.dbg.declare(metadata !{%class.A* %a}, metadata !113, metadata !{i32 786690}), !dbg !114
   call void @_ZN1B9AInstanceEv(%class.A* sret %a, %class.B* %b), !dbg !114
   %0 = load i32* %return_val, align 4, !dbg !115
   store i32 %0, i32* %retval, !dbg !115
@@ -193,7 +193,7 @@ define linkonce_odr void @_ZN1BC2Ev(%class.B* %this) unnamed_addr #0 align 2 {
 entry:
   %this.addr = alloca %class.B*, align 8
   store %class.B* %this, %class.B** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.B** %this.addr}, metadata !123), !dbg !124
+  call void @llvm.dbg.declare(metadata !{%class.B** %this.addr}, metadata !123, metadata !{i32 786690}), !dbg !124
   %this1 = load %class.B** %this.addr
   ret void, !dbg !125
 }
@@ -218,7 +218,7 @@ entry:
   %exn.slot = alloca i8*
   %ehselector.slot = alloca i32
   store %class.A* %this, %class.A** %this.addr, align 8
-  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !126), !dbg !127
+  call void @llvm.dbg.declare(metadata !{%class.A** %this.addr}, metadata !126, metadata !{i32 786690}), !dbg !127
   %this1 = load %class.A** %this.addr
   invoke void @_ZN1AD2Ev(%class.A* %this1)
           to label %invoke.cont unwind label %lpad, !dbg !128