Commit Graph

14950 Commits

Author SHA1 Message Date
Owen Anderson
ed5707baf9 DAGCombine should not aggressively fold SEXT(VSETCC(...)) into a wider VSETCC without first checking the target's vector boolean contents.
This exposed an issue with PowerPC AltiVec where it appears it was setting the wrong vector boolean contents.  The included change
fixes the PowerPC tests, and was OK'd by Hal.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180129 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 18:09:28 +00:00
Stephen Lin
13aba14eb5 Add some constraints to use of 'returned':
1) Disallow 'returned' on parameter that is also 'sret' (no sensible semantics, as far as I can tell).
2) Conservatively disallow tail calls through 'returned' parameters that also are 'zext' or 'sext' (for consistency with treatment of other zero-extending and sign-extending operations in tail call position detection...can be revised later to handle situations that can be determined to be safe).

This is a new attribute that is not yet used, so there is no impact.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180118 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-23 16:31:56 +00:00
Matt Arsenault
9a0e12a6ed Remove unused DwarfSectionOffsetDirective string
The value isn't actually used, and setting it emits a COFF specific
directive.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180064 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 22:49:11 +00:00
Eric Christopher
3e39731e88 Move C++ code out of the C headers and into either C++ headers
or the C++ files themselves. This enables people to use
just a C compiler to interoperate with LLVM.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180063 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 22:47:22 +00:00
Eli Bendersky
2ad047e04d Optimize MachineBasicBlock::getSymbol by caching the symbol. Since the symbol
name computation is expensive, this helps save about 25% of the time spent in
this function.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180049 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 21:21:08 +00:00
Rafael Espindola
cde25b435a Clarify that llvm.used can contain aliases.
Also add a check for llvm.used in the verifier and simplify clients now that
they can assume they have a ConstantArray.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180019 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 14:58:02 +00:00
Eric Christopher
1b0cd2f2a6 Tidy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@180000 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 07:51:08 +00:00
Eric Christopher
6c3bb94445 Update comment. Whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179999 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 07:47:40 +00:00
David Blaikie
c462db6d66 Revert "Revert "PR14606: debug info imported_module support""
This reverts commit r179840 with a fix to test/DebugInfo/two-cus-from-same-file.ll

I'm not sure why that test only failed on ARM & MIPS and not X86 Linux, even
though the debug info was clearly invalid on all of them, but this ought to fix
it.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179996 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-22 06:12:31 +00:00
Jim Grosbach
0cb1019e9c Legalize vector truncates by parts rather than just splitting.
Rather than just splitting the input type and hoping for the best, apply
a bit more cleverness. Just splitting the types until the source is
legal often leads to an illegal result time, which is then widened and a
scalarization step is introduced which leads to truly horrible code
generation. With the loop vectorizer, these sorts of operations are much
more common, and so it's worth extra effort to do them well.

Add a legalization hook for the operands of a TRUNCATE node, which will
be encountered after the result type has been legalized, but if the
operand type is still illegal. If simple splitting of both types
ends up with the result type of each half still being legal, just
do that (v16i16 -> v16i8 on ARM, for example). If, however, that would
result in an illegal result type (v8i32 -> v8i8 on ARM, for example),
we can get more clever with power-two vectors. Specifically,
split the input type, but also widen the result element size, then
concatenate the halves and truncate again.  For example on ARM,
To perform a "%res = v8i8 trunc v8i32 %in" we transform to:
  %inlo = v4i32 extract_subvector %in, 0
  %inhi = v4i32 extract_subvector %in, 4
  %lo16 = v4i16 trunc v4i32 %inlo
  %hi16 = v4i16 trunc v4i32 %inhi
  %in16 = v8i16 concat_vectors v4i16 %lo16, v4i16 %hi16
  %res = v8i8 trunc v8i16 %in16

This allows instruction selection to generate three VMOVN instructions
instead of a sequences of moves, stores and loads.

Update the ARMTargetTransformInfo to take this improved legalization
into account.

Consider the simplified IR:

define <16 x i8> @test1(<16 x i32>* %ap) {
  %a = load <16 x i32>* %ap
  %tmp = trunc <16 x i32> %a to <16 x i8>
  ret <16 x i8> %tmp
}

define <8 x i8> @test2(<8 x i32>* %ap) {
  %a = load <8 x i32>* %ap
  %tmp = trunc <8 x i32> %a to <8 x i8>
  ret <8 x i8> %tmp
}

Previously, we would generate the truly hideous:
	.syntax unified
	.section	__TEXT,__text,regular,pure_instructions
	.globl	_test1
	.align	2
_test1:                                 @ @test1
@ BB#0:
	push	{r7}
	mov	r7, sp
	sub	sp, sp, #20
	bic	sp, sp, #7
	add	r1, r0, #48
	add	r2, r0, #32
	vld1.64	{d24, d25}, [r0:128]
	vld1.64	{d16, d17}, [r1:128]
	vld1.64	{d18, d19}, [r2:128]
	add	r1, r0, #16
	vmovn.i32	d22, q8
	vld1.64	{d16, d17}, [r1:128]
	vmovn.i32	d20, q9
	vmovn.i32	d18, q12
	vmov.u16	r0, d22[3]
	strb	r0, [sp, #15]
	vmov.u16	r0, d22[2]
	strb	r0, [sp, #14]
	vmov.u16	r0, d22[1]
	strb	r0, [sp, #13]
	vmov.u16	r0, d22[0]
	vmovn.i32	d16, q8
	strb	r0, [sp, #12]
	vmov.u16	r0, d20[3]
	strb	r0, [sp, #11]
	vmov.u16	r0, d20[2]
	strb	r0, [sp, #10]
	vmov.u16	r0, d20[1]
	strb	r0, [sp, #9]
	vmov.u16	r0, d20[0]
	strb	r0, [sp, #8]
	vmov.u16	r0, d18[3]
	strb	r0, [sp, #3]
	vmov.u16	r0, d18[2]
	strb	r0, [sp, #2]
	vmov.u16	r0, d18[1]
	strb	r0, [sp, #1]
	vmov.u16	r0, d18[0]
	strb	r0, [sp]
	vmov.u16	r0, d16[3]
	strb	r0, [sp, #7]
	vmov.u16	r0, d16[2]
	strb	r0, [sp, #6]
	vmov.u16	r0, d16[1]
	strb	r0, [sp, #5]
	vmov.u16	r0, d16[0]
	strb	r0, [sp, #4]
	vldmia	sp, {d16, d17}
	vmov	r0, r1, d16
	vmov	r2, r3, d17
	mov	sp, r7
	pop	{r7}
	bx	lr

	.globl	_test2
	.align	2
_test2:                                 @ @test2
@ BB#0:
	push	{r7}
	mov	r7, sp
	sub	sp, sp, #12
	bic	sp, sp, #7
	vld1.64	{d16, d17}, [r0:128]
	add	r0, r0, #16
	vld1.64	{d20, d21}, [r0:128]
	vmovn.i32	d18, q8
	vmov.u16	r0, d18[3]
	vmovn.i32	d16, q10
	strb	r0, [sp, #3]
	vmov.u16	r0, d18[2]
	strb	r0, [sp, #2]
	vmov.u16	r0, d18[1]
	strb	r0, [sp, #1]
	vmov.u16	r0, d18[0]
	strb	r0, [sp]
	vmov.u16	r0, d16[3]
	strb	r0, [sp, #7]
	vmov.u16	r0, d16[2]
	strb	r0, [sp, #6]
	vmov.u16	r0, d16[1]
	strb	r0, [sp, #5]
	vmov.u16	r0, d16[0]
	strb	r0, [sp, #4]
	ldm	sp, {r0, r1}
	mov	sp, r7
	pop	{r7}
	bx	lr

Now, however, we generate the much more straightforward:
	.syntax unified
	.section	__TEXT,__text,regular,pure_instructions
	.globl	_test1
	.align	2
_test1:                                 @ @test1
@ BB#0:
	add	r1, r0, #48
	add	r2, r0, #32
	vld1.64	{d20, d21}, [r0:128]
	vld1.64	{d16, d17}, [r1:128]
	add	r1, r0, #16
	vld1.64	{d18, d19}, [r2:128]
	vld1.64	{d22, d23}, [r1:128]
	vmovn.i32	d17, q8
	vmovn.i32	d16, q9
	vmovn.i32	d18, q10
	vmovn.i32	d19, q11
	vmovn.i16	d17, q8
	vmovn.i16	d16, q9
	vmov	r0, r1, d16
	vmov	r2, r3, d17
	bx	lr

	.globl	_test2
	.align	2
_test2:                                 @ @test2
@ BB#0:
	vld1.64	{d16, d17}, [r0:128]
	add	r0, r0, #16
	vld1.64	{d18, d19}, [r0:128]
	vmovn.i32	d16, q8
	vmovn.i32	d17, q9
	vmovn.i16	d16, q8
	vmov	r0, r1, d16
	bx	lr

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179989 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-21 23:47:41 +00:00
Jim Grosbach
1e48093df8 Tidy up comment grammar.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179986 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-21 21:23:01 +00:00
Tim Northover
8b71994fde Remove unused ShouldFoldAtomicFences flag.
I think it's almost impossible to fold atomic fences profitably under
LLVM/C++11 semantics. As a result, this is now unused and just
cluttering up the target interface.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179940 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-20 12:32:43 +00:00
Tim Northover
6265d5c91a Remove unused MEMBARRIER DAG node; it's been replaced by ATOMIC_FENCE.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179939 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-20 12:32:17 +00:00
Stephen Lin
456ca048af Add CodeGen support for functions that always return arguments via a new parameter attribute 'returned', which is taken advantage of in target-independent tail call opportunity detection and in ARM call lowering (when placed on an integral first parameter).
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179925 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-20 05:14:40 +00:00
Stephen Lin
5c34e08b9f Allow tail call opportunity detection through nested and/or multiple iterations of extractelement/insertelement indirection
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179924 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-20 04:27:51 +00:00
Eli Bendersky
462123f661 Simplify the code in FastISel::tryToFoldLoad, add an assertion and fix a comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179908 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 23:26:18 +00:00
Eli Bendersky
75299e3a95 Move TryToFoldFastISelLoad to FastISel, where it belongs. In general, I'm
trying to move as much FastISel logic as possible out of the main path in
SelectionDAGISel - intermixing them just adds confusion.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179902 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 22:29:18 +00:00
Michael Liao
2a8bea7a8e ArrayRefize getMachineNode(). No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179901 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 22:22:57 +00:00
Jakob Stoklund Olesen
a58d67af29 Add an MRI::verifyUseLists() function.
This checks the sanity of the register use lists in the MI intermediate
representation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179895 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 21:40:57 +00:00
Eli Bendersky
03494e05e8 Use dbgs() consistently for -debug printouts
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179894 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 21:37:07 +00:00
Eric Christopher
41201ed06f Revert "PR14606: debug info imported_module support"
This reverts commit r179836 as it seems to have caused test failures.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179840 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 07:47:16 +00:00
David Blaikie
bcb81360a2 PR14606: debug info imported_module support
Adding another CU-wide list, in this case of imported_modules (since they
should be relatively rare, it seemed better to add a list where each element
had a "context" value, rather than add a (usually empty) list to every scope).
This takes care of DW_TAG_imported_module, but to fully address PR14606 we'll
need to expand this to cover DW_TAG_imported_declaration too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179836 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 06:57:04 +00:00
Eli Bendersky
5bd0767a04 Add some more stats for fast isel vs. SelectionDAG, w.r.t lowering function
arguments in entry BBs.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179824 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-19 01:04:40 +00:00
Peter Collingbourne
df39be6cb4 Add support for subsections to the ELF assembler. Fixes PR8717.
Differential Revision: http://llvm-reviews.chandlerc.com/D598

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179725 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-17 21:18:16 +00:00
Andy Gibbs
604b3573f9 Replace uses of the deprecated std::auto_ptr with OwningPtr.
This is a rework of the broken parts in r179373 which were subsequently reverted in r179374 due to incompatibility with C++98 compilers.  This version should be ok under C++98.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179520 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-15 12:06:32 +00:00
Nadav Rotem
420820056d Document the decision to assume that the cost of floats is twice as much as integers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179478 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-14 05:55:18 +00:00
Andrew Trick
baedcd7977 MI-Sched: DEBUG formatting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179452 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-13 06:07:49 +00:00
Andrew Trick
6a22dba485 MI-Sched cleanup. If an instruction has no valid sched class, do not attempt to check for a variant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179451 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-13 06:07:45 +00:00
Andrew Trick
4392f0f407 MI-Sched: schedule physreg copies.
The register allocator expects minimal physreg live ranges. Schedule
physreg copies accordingly. This is slightly tricky when they occur in
the middle of the scheduling region. For now, this is handled by
rescheduling the copy when its associated instruction is
scheduled. Eventually we may instead bundle them, but only if we can
preserve the bundles as parallel copies during regalloc.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179449 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-13 06:07:40 +00:00
Nadav Rotem
9eb366acba CostModel: increase the default cost of supported floating point operations from 1 to two. Fixed a few tests that changes because now the cost of one insert + a vector operation on two doubles is lower than two scalar operations on doubles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179413 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 21:15:03 +00:00
Benjamin Kramer
3389e10d67 Revert broken pieces of r179373.
You can't copy an OwningPtr, and move semantics aren't available in C++98.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179374 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 12:13:51 +00:00
Andy Gibbs
200241e4de Replace uses of the deprecated std::auto_ptr with OwningPtr.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179373 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 10:56:28 +00:00
Nadav Rotem
33a47d66e9 Don't disable block layout when forcing block alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179355 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 01:24:16 +00:00
Nadav Rotem
07706e5506 Add a flag to align all basic blocks in the function.
When debugging performance regressions we often ask ourselves if the regression
that we see is due to poor isel/sched/ra or due to some micro-architetural
problem.  When comparing two code sequences one good way to rule out front-end
bottlenecks (and other the issues) is to force code alignment. This pass adds
a flag that forces the alignment of all of the basic blocks in the program.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179353 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-12 00:48:32 +00:00
Benjamin Kramer
fdca221290 Add braces around || in && to pacify GCC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179275 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-11 11:57:01 +00:00
Hal Finkel
9af7014019 Manually remove successors in if conversion when CopyAndPredicateBlock is used
In the simple and triangle if-conversion cases, when CopyAndPredicateBlock is
used because the to-be-predicated block has other predecessors, we need to
explicitly remove the old copied block from the successors list. Normally if
conversion relies on TII->AnalyzeBranch combined with BB->CorrectExtraCFGEdges
to cleanup the successors list, but if the predicated block contained an
un-analyzable branch (such as a now-predicated return), then this will fail.

These extra successors were causing a problem on PPC because it was causing
later passes (such as PPCEarlyReturm) to leave dead return-only basic blocks in
the code.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179227 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-10 22:05:25 +00:00
Andrew Trick
5ed028385c Generalize the PassConfig API and remove addFinalizeRegAlloc().
The target hooks are getting out of hand. What does it mean to run
before or after regalloc anyway? Allowing either Pass* or AnalysisID
pass identification should make it much easier for targets to use the
substitutePass and insertPass APIs, and create less need for badly
named target hooks.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179140 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-10 01:06:56 +00:00
Eric Christopher
e0828ec602 The .dwo section shouldn't contain the unrelocated values (and
therefore not at all) of the pc or statement list. We also don't
need to emit the compilation dir so save so space and time
and don't bother.

Fix up the testcase accordingly and verify that we don't emit
the attributes or the items that they use.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179114 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-09 19:23:15 +00:00
Benjamin Kramer
6fac1fbf30 DAGCombiner: Fold a shuffle on CONCAT_VECTORS into a new CONCAT_VECTORS if possible.
This pattern occurs in SROA output due to the way vector arguments are lowered
on ARM.

The testcase from PR15525 now compiles into this, which is better than the code
we got with the old scalarrepl:
_Store:
	ldr.w	r9, [sp]
	vmov	d17, r3, r9
	vmov	d16, r1, r2
	vst1.8	{d16, d17}, [r0]
	bx	lr

Differential Revision: http://llvm-reviews.chandlerc.com/D647

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179106 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-09 17:41:43 +00:00
Eric Christopher
9a9e73b47d DW_FORM_sec_offset should be a relocation on platforms that use
a relocation across sections. Do this for DW_AT_stmt list in the
skeleton CU and check the relocations in the debug_info section.

Add a FIXME for multiple CUs.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178969 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-07 03:43:09 +00:00
Nadav Rotem
6e01dcbb73 typo
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178949 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-06 04:24:12 +00:00
Manman Ren
5044a9395a Dwarf: use utostr on CUID to append to SmallString.
We used to do "SmallString += CUID", which is incorrect, since CUID will
be truncated to a char.

rdar://problem/13573833


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178941 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-06 01:02:38 +00:00
Hal Finkel
2e80991a77 Reapply r178845 with fix - Fix bug in PEI's virtual-register scavenging
This fixes PEI as previously described, but correctly handles the case where
the instruction defining the virtual register to be scavenged is the first in
the block. Arnold provided me with a bugpoint-reduced test case, but even that
seems too large to use as a regression test. If I'm successful in cleaning it
up then I'll commit that as well.

Original commit message:

    This change fixes a bug that I introduced in r178058. After a register is
    scavenged using one of the available spills slots the instruction defining the
    virtual register needs to be moved to after the spill code. The scavenger has
    already processed the defining instruction so that registers killed by that
    instruction are available for definition in that same instruction. Unfortunately,
    after this, the scavenger needs to iterate through the spill code and then
    visit, again, the instruction that defines the now-scavenged register. In order
    to avoid confusion, the register scavenger needs the ability to 'back up'
    through the spill code so that it can again process the instructions in the
    appropriate order. Prior to this fix, once the scavenger reached the
    just-moved instruction, it would assert if it killed any registers because,
    having already processed the instruction, it believed they were undefined.

    Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
    for diagnosing the problem and testing this fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178919 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 22:31:56 +00:00
Bill Wendling
13bbe1f52e Use the target options specified on a function to reset the back-end.
During LTO, the target options on functions within the same Module may
change. This would necessitate resetting some of the back-end. Do this for X86,
because it's a Friday afternoon.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178917 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 21:52:40 +00:00
Hal Finkel
b6cfeb63f8 Revert r178845 - Fix bug in PEI's virtual-register scavenging
Reverting because this breaks one of the LTO builders. Original commit message:

    This change fixes a bug that I introduced in r178058. After a register is
    scavenged using one of the available spills slots the instruction defining the
    virtual register needs to be moved to after the spill code. The scavenger has
    already processed the defining instruction so that registers killed by that
    instruction are available for definition in that same instruction. Unfortunately,
    after this, the scavenger needs to iterate through the spill code and then
    visit, again, the instruction that defines the now-scavenged register. In order
    to avoid confusion, the register scavenger needs the ability to 'back up'
    through the spill code so that it can again process the instructions in the
    appropriate order. Prior to this fix, once the scavenger reached the
    just-moved instruction, it would assert if it killed any registers because,
    having already processed the instruction, it believed they were undefined.

    Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
    for diagnosing the problem and testing this fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178916 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 21:30:40 +00:00
Hal Finkel
afe2f43e4e Fix bug in PEI's virtual-register scavenging
This change fixes a bug that I introduced in r178058. After a register is
scavenged using one of the available spills slots the instruction defining the
virtual register needs to be moved to after the spill code. The scavenger has
already processed the defining instruction so that registers killed by that
instruction are available for definition in that same instruction. Unfortunately,
after this, the scavenger needs to iterate through the spill code and then
visit, again, the instruction that defines the now-scavenged register. In order
to avoid confusion, the register scavenger needs the ability to 'back up'
through the spill code so that it can again process the instructions in the
appropriate order. Prior to this fix, once the scavenger reached the
just-moved instruction, it would assert if it killed any registers because,
having already processed the instruction, it believed they were undefined.

Unfortunately, I don't yet have a small test case. Thanks to Pranav Bhandarkar
for diagnosing the problem and testing this fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178845 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 05:01:13 +00:00
Andrew Trick
614dacc910 RegisterPressure heuristics currently require signed comparisons.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178823 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 00:31:34 +00:00
Andrew Trick
2182977ff2 Disable DFSResult for ConvergingScheduler.
For now, just save the compile time since the ConvergingScheduler
heuristics don't use this analysis. We'll probably enable it later
after compile-time investigation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178822 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 00:31:31 +00:00
Andrew Trick
11189f7a01 MachineScheduler: format DEBUG output.
I'm getting more serious about tuning and enabling on x86/ARM. Start
by making the trace readable.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178821 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-05 00:31:29 +00:00
Arnold Schwaighofer
6bf4f67641 CostModel: Add parameter to instruction cost to further classify operand values
On certain architectures we can support efficient vectorized version of
instructions if the operand value is uniform (splat) or a constant scalar.
An example of this is a vector shift on x86.

We can efficiently support

for (i = 0 ; i < ; i += 4)
  w[0:3] = v[0:3] << <2, 2, 2, 2>

but not

for (i = 0; i < ; i += 4)
  w[0:3] = v[0:3] << x[0:3]

This patch adds a parameter to getArithmeticInstrCost to further qualify operand
values as uniform or uniform constant.

Targets can then choose to return a different cost for instructions with such
operand values.

A follow-up commit will test this feature on x86.

radar://13576547

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178807 91177308-0d34-0410-b5e6-96231b3b80d8
2013-04-04 23:26:21 +00:00