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, 15 insertions, 15 deletions

diff --git a/llvm/test/CodeGen/ARM/debug-info-blocks.ll b/llvm/test/CodeGen/ARM/debug-info-blocks.ll
index 2b1513c1e8b..1e061388e97 100644
--- a/llvm/test/CodeGen/ARM/debug-info-blocks.ll
+++ b/llvm/test/CodeGen/ARM/debug-info-blocks.ll
@@ -19,11 +19,11 @@ target triple = "thumbv7-apple-ios"
 @"OBJC_IVAR_$_MyWork._data" = external hidden global i32, section "__DATA, __objc_const", align 4
 @"\01L_OBJC_SELECTOR_REFERENCES_222" = external hidden global i8*, section "__DATA, __objc_selrefs, literal_pointers, no_dead_strip"
 
-declare void @llvm.dbg.declare(metadata, metadata) nounwind readnone
+declare void @llvm.dbg.declare(metadata, metadata, metadata) nounwind readnone
 
 declare i8* @objc_msgSend(i8*, i8*, ...)
 
-declare void @llvm.dbg.value(metadata, i64, metadata) nounwind readnone
+declare void @llvm.dbg.value(metadata, i64, metadata, metadata) nounwind readnone
 
 declare void @llvm.memcpy.p0i8.p0i8.i32(i8* nocapture, i8* nocapture, i32, i32, i1) nounwind
 
@@ -31,22 +31,22 @@ define hidden void @foobar_func_block_invoke_0(i8* %.block_descriptor, %0* %load
   %1 = alloca %0*, align 4
   %bounds = alloca %struct.CR, align 4
   %data = alloca %struct.CR, align 4
-  call void @llvm.dbg.value(metadata !{i8* %.block_descriptor}, i64 0, metadata !27), !dbg !129
+  call void @llvm.dbg.value(metadata !{i8* %.block_descriptor}, i64 0, metadata !27, metadata !{i32 786690}), !dbg !129
   store %0* %loadedMydata, %0** %1, align 4
-  call void @llvm.dbg.declare(metadata !{%0** %1}, metadata !130), !dbg !131
+  call void @llvm.dbg.declare(metadata !{%0** %1}, metadata !130, metadata !{i32 786690}), !dbg !131
   %2 = bitcast %struct.CR* %bounds to %1*
   %3 = getelementptr %1* %2, i32 0, i32 0
   store [4 x i32] %bounds.coerce0, [4 x i32]* %3
-  call void @llvm.dbg.declare(metadata !{%struct.CR* %bounds}, metadata !132), !dbg !133
+  call void @llvm.dbg.declare(metadata !{%struct.CR* %bounds}, metadata !132, metadata !{i32 786690}), !dbg !133
   %4 = bitcast %struct.CR* %data to %1*
   %5 = getelementptr %1* %4, i32 0, i32 0
   store [4 x i32] %data.coerce0, [4 x i32]* %5
-  call void @llvm.dbg.declare(metadata !{%struct.CR* %data}, metadata !134), !dbg !135
+  call void @llvm.dbg.declare(metadata !{%struct.CR* %data}, metadata !134, metadata !{i32 786690}), !dbg !135
   %6 = bitcast i8* %.block_descriptor to %2*
   %7 = getelementptr inbounds %2* %6, i32 0, i32 6
-  call void @llvm.dbg.declare(metadata !{%2* %6}, metadata !136), !dbg !137
-  call void @llvm.dbg.declare(metadata !{%2* %6}, metadata !138), !dbg !137
-  call void @llvm.dbg.declare(metadata !{%2* %6}, metadata !139), !dbg !140
+  call void @llvm.dbg.declare(metadata !{%2* %6}, metadata !136, metadata !163), !dbg !137
+  call void @llvm.dbg.declare(metadata !{%2* %6}, metadata !138, metadata !164), !dbg !137
+  call void @llvm.dbg.declare(metadata !{%2* %6}, metadata !139, metadata !165), !dbg !140
   %8 = load %0** %1, align 4, !dbg !141
   %9 = load i8** @"\01L_OBJC_SELECTOR_REFERENCES_13", !dbg !141
   %10 = bitcast %0* %8 to i8*, !dbg !141
@@ -231,10 +231,10 @@ define hidden void @foobar_func_block_invoke_0(i8* %.block_descriptor, %0* %load
 !133 = metadata !{i32 609, i32 175, metadata !23, null}
 !134 = metadata !{i32 786689, metadata !23, metadata !"data", metadata !24, i32 67109473, metadata !108, i32 0, null} ; [ DW_TAG_arg_variable ]
 !135 = metadata !{i32 609, i32 190, metadata !23, null}
-!136 = metadata !{i32 786688, metadata !23, metadata !"mydata", metadata !24, i32 604, metadata !50, i32 0, null, metadata !163} ; [ DW_TAG_auto_variable ]
+!136 = metadata !{i32 786688, metadata !23, metadata !"mydata", metadata !24, i32 604, metadata !50, i32 0, null} ;; [ DW_TAG_auto_variable ]
 !137 = metadata !{i32 604, i32 49, metadata !23, null}
-!138 = metadata !{i32 786688, metadata !23, metadata !"self", metadata !40, i32 604, metadata !90, i32 0, null, metadata !164} ; [ DW_TAG_auto_variable ]
-!139 = metadata !{i32 786688, metadata !23, metadata !"semi", metadata !24, i32 607, metadata !125, i32 0, null, metadata !165} ; [ DW_TAG_auto_variable ]
+!138 = metadata !{i32 786688, metadata !23, metadata !"self", metadata !40, i32 604, metadata !90, i32 0, null} ;; [ DW_TAG_auto_variable ]
+!139 = metadata !{i32 786688, metadata !23, metadata !"semi", metadata !24, i32 607, metadata !125, i32 0, null} ;; [ DW_TAG_auto_variable ]
 !140 = metadata !{i32 607, i32 30, metadata !23, null}
 !141 = metadata !{i32 610, i32 17, metadata !142, null}
 !142 = metadata !{i32 786443, metadata !152, metadata !23, i32 609, i32 200, i32 94} ; [ DW_TAG_lexical_block ]
@@ -258,6 +258,6 @@ define hidden void @foobar_func_block_invoke_0(i8* %.block_descriptor, %0* %load
 !160 = metadata !{metadata !"header.h", metadata !"/Volumes/Sandbox/llvm"}
 !161 = metadata !{metadata !"header2.h", metadata !"/Volumes/Sandbox/llvm"}
 !162 = metadata !{i32 1, metadata !"Debug Info Version", i32 1}
-!163 = metadata !{i64 1, i64 20, i64 2, i64 1, i64 4, i64 2, i64 1, i64 24}
-!164 = metadata !{i64 1, i64 24}
-!165 = metadata !{i64 1, i64 28}
+!163 = metadata !{i32 786690, i64 34, i64 20, i64 6, i64 34, i64 4, i64 6, i64 34, i64 24} ; [DW_OP_plus 20 DW_OP_deref DW_OP_plus 4 DW_OP_deref DW_OP_plus 24]
+!164 = metadata !{i32 786690, i64 34, i64 24} ; [DW_OP_plus 24]
+!165 = metadata !{i32 786690, i64 34, i64 28} ; [DW_OP_plus 28]