llvm-project/llvm/test/CodeGen
Adrian Prantl 25a7174e7a 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!

llvm-svn: 218778
2014-10-01 17:55:39 +00:00
..
AArch64 Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
ARM Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
CPP IR: add "cmpxchg weak" variant to support permitted failure. 2014-06-13 14:24:07 +00:00
Generic Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
Hexagon Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
Inputs Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
MSP430 Drop the W postfix on the 16-bit registers. 2014-09-10 06:58:14 +00:00
Mips [mips] For indirect calls we don't need $gp to point to .got. Mips linker 2014-10-01 08:22:21 +00:00
NVPTX Revert r216862 due to a performance regression 2014-10-01 15:22:13 +00:00
PowerPC Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
R600 R600: Call EmitFunctionHeader() in the AsmPrinter to populate the ELF symbol table 2014-10-01 17:15:17 +00:00
SPARC Add back tests for empty function in SPARC and PowerPC. 2014-09-15 22:11:07 +00:00
SystemZ IR: add "cmpxchg weak" variant to support permitted failure. 2014-06-13 14:24:07 +00:00
Thumb Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
Thumb2 [ARM] Allow selecting VRINT[APMXZR] and VCVT[BT] instructions for FPv5 2014-10-01 13:13:18 +00:00
X86 Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00
XCore Move the complex address expression out of DIVariable and into an extra 2014-10-01 17:55:39 +00:00