Commit Graph

109038 Commits

Author SHA1 Message Date
Chris Bieneman
c14fb89680 Defining a new API for debug options that doesn't rely on static global cl::opts.
Summary:
This is based on the discussions from the LLVMDev thread:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2014-August/075886.html

Reviewers: chandlerc

Reviewed By: chandlerc

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D5389

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219854 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 21:54:35 +00:00
Tom Stellard
d3fc10a525 R600/SI: Fix bug where immediates were being used in DS addr operands
The SelectDS1Addr1Offset complex pattern always tries to store constant
lds pointers in the offset operand and store a zero value in the addr operand.
Since the addr operand does not accept immediates, the zero value
needs to first be copied to a register.

This newly created zero value will not go through normal instruction
selection, so we need to manually insert a V_MOV_B32_e32 in the complex
pattern.

This bug was hidden by the fact that if there was another zero value
in the DAG that had not been selected yet, then the CSE done by the DAG
would use the unselected node for the addr operand rather than the one
that was just created.  This would lead to the zero value being selected
and the DAG automatically inserting a V_MOV_B32_e32 instruction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219848 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 21:08:59 +00:00
Eric Christopher
55751ba9e2 Avoid caching the MachineFunction, we don't use it outside of
runOnMachineFunction.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219847 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 21:06:25 +00:00
Sid Manning
0a72d8bb20 Wrong attribute. LLVM_ATTRIBUTE_UNUSED not LLVM_ATTRIBUTE_USED
This original fix for the build break was correct.  LLVM_ATTRIBUTE_USED
removes the warning message because it keeps the function in the object
file.  LLVM_ATTRIBUTE_UNUSED indicates that it may or may not be used
depending on build settings.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219846 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 20:41:17 +00:00
Duncan P. N. Exon Smith
9ca230f11c IR: Move NumOperands from User to Value, NFC
Store `User::NumOperands` (and `MDNode::NumOperands`) in `Value`.

On 64-bit host architectures, this reduces `sizeof(User)` and all
subclasses by 8, and has no effect on `sizeof(Value)` (or, incidentally,
on `sizeof(MDNode)`).

On 32-bit host architectures, this increases `sizeof(Value)` by 4.
However, it has no effect on `sizeof(User)` and `sizeof(MDNode)`, so the
only concrete subclasses of `Value` that actually see the increase are
`BasicBlock`, `Argument`, `InlineAsm`, and `MDString`.  Moreover, I'll
be shocked and confused if this causes a tangible memory regression.

This has no functionality change (other than memory footprint).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219845 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 20:39:05 +00:00
Duncan P. N. Exon Smith
40dd9d68d7 IR: Cleanup comments for Value, User, and MDNode
A follow-up commit will modify the memory-layout of `Value`, `User`, and
`MDNode`.  First fix the comments to be doxygen-friendly (and to follow
the coding standards).

  - Use "\brief" instead of "repeatedName -".
  - Add a brief intro where it was missing.
  - Remove duplicated comments from source files (and a couple of
    noisy/trivial comments altogether).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219844 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 20:28:31 +00:00
Sid Manning
a169d59437 Wrong attribute. LLVM_ATTRIBUTE_USED not LLVM_ATTRIBUTE_UNUSED
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219837 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 19:32:52 +00:00
Rafael Espindola
fc6e0f6f87 Allow forward references to section symbols.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219835 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 19:30:18 +00:00
Sanjoy Das
40edbf130e Teach ScalarEvolution to sharpen range information.
If x is known to have the range [a, b) in a loop predicated by (icmp
ne x, a), its range can be sharpened to [a + 1, b).  Get
ScalarEvolution and hence IndVars to exploit this fact.
    
This change triggers an optimization to widen-loop-comp.ll, so it had
to be edited to get it to pass.

phabricator: http://reviews.llvm.org/D5639



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219834 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 19:25:28 +00:00
Sid Manning
f0f7ec31d4 Add LLVM_ATTRIBUTE_UNUSED to function currently just used in an assert
Fixes break when -Wunused-function is used.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219833 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 19:24:14 +00:00
Akira Hatanaka
38537634e2 InstCombine: Narrow switch instructions using known bits.
Truncate the operands of a switch instruction to a narrower type if the upper
bits are known to be all ones or zeros.

rdar://problem/17720004


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219832 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 19:05:50 +00:00
Juergen Ributzka
7440a83e60 Reapply "[FastISel][AArch64] Add custom lowering for GEPs."
This is mostly a copy of the existing FastISel GEP code, but we have to
duplicate it for AArch64, because otherwise we would bail out even for simple
cases. This is because the standard fastEmit functions don't cover MUL at all
and ADD is lowered very inefficientily.

The original commit had a bug in the add emit logic, which has been fixed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219831 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 18:58:07 +00:00
Juergen Ributzka
32c5fde3f1 [FastISel][AArch64] Factor out add with immediate emission into a helper function. NFC.
Simplify add with immediate emission by factoring it out into a helper function.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219830 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 18:58:02 +00:00
Rafael Espindola
ad04f5db82 Correctly handle references to section symbols.
When processing assembly like

.long .text

we were creating a new undefined symbol .text. GAS on the other hand would
handle that as a reference to the .text section.

This patch implements that by creating the section symbols earlier so that
they are visible during asm parsing.

The patch also updates llvm-readobj to print the symbol number in the relocation
dump so that the test can differentiate between two sections with the same name.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219829 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 18:55:30 +00:00
Sid Manning
1338612c55 Enable the instruction printer in HexagonMCTargetDesc
This adds the MCInstPrinter to the LLVMHexagonDesc library and removes
the dependency LLVMHexagonAsmPrinter had on LLVMHexagonDesc. This is
a prerequisite needed by the disassembler.

Phabricator Revision: http://reviews.llvm.org/D5734

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219826 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 18:27:40 +00:00
Matt Arsenault
8b3a9205b7 R600/SI: Also try to use 0 base for misaligned 8-byte DS loads.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219823 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 18:06:43 +00:00
Matt Arsenault
7fdd553b66 R600: Fix miscompiles when BFE has multiple uses
SimplifyDemandedBits would break the other uses of the operand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219819 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:58:34 +00:00
Sanjay Patel
ddcfe81459 correct const-ness with auto and dyn_cast
1. Use const with autos.
2. Don't bother with explicit const in cast ops because they do it automagically.

Thanks, David B. / Aaron B. / Reid K.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219817 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:45:13 +00:00
Hal Finkel
6c15862fd3 [SLPVectorize] Basic ephemeral-value awareness
The SLP vectorizer should not vectorize ephemeral values. These are used to
express information to the optimizer, and vectorizing them does not lead to
faster code (because the ephemeral values are dropped prior to code generation,
vectorized or not), and obscures the information the instructions are
attempting to communicate (the logic that interprets the arguments to
@llvm.assume generically does not understand vectorized conditions).

Also, uses by ephemeral values are free (because they, and the necessary
extractelement instructions, will be dropped prior to code generation).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219816 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:35:01 +00:00
Hal Finkel
9819bcf7f1 Treat the WorkSet used to find ephemeral values as double-ended
We need to make sure that we visit all operands of an instruction before moving
deeper in the operand graph. We had been pushing operands onto the back of the work
set, and popping them off the back as well, meaning that we might visit an
instruction before visiting all of its uses that sit in between it and the call
to @llvm.assume.

To provide an explicit example, given the following:
  %q0 = extractelement <4 x float> %rd, i32 0
  %q1 = extractelement <4 x float> %rd, i32 1
  %q2 = extractelement <4 x float> %rd, i32 2
  %q3 = extractelement <4 x float> %rd, i32 3
  %q4 = fadd float %q0, %q1
  %q5 = fadd float %q2, %q3
  %q6 = fadd float %q4, %q5
  %qi = fcmp olt float %q6, %q5
  call void @llvm.assume(i1 %qi)

%q5 is used by both %qi and %q6. When we visit %qi, it will be marked as
ephemeral, and we'll queue %q6 and %q5. %q6 will be marked as ephemeral and
we'll queue %q4 and %q5. Under the old system, we'd then visit %q4, which
would become ephemeral, %q1 and then %q0, which would become ephemeral as
well, and now we have a problem. We'd visit %rd, but it would not be marked as
ephemeral because we've not yet visited %q2 and %q3 (because we've not yet
visited %q5).

This will be covered by a test case in a follow-up commit that enables
ephemeral-value awareness in the SLP vectorizer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219815 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:34:48 +00:00
Derek Schuff
279b5504a3 [MC] Make bundle alignment mode setting idempotent and support nested bundles
Summary:
Currently an error is thrown if bundle alignment mode is set more than once
per module (either via the API or the .bundle_align_mode directive). This
change allows setting it multiple times as long as the alignment doesn't
change.

Also nested bundle_lock groups are currently not allowed. This change allows
them, with the effect that the group stays open until all nests are exited,
and if any of the bundle_lock directives has the align_to_end flag, the
group becomes align_to_end.

These changes make the bundle aligment simpler to use in the compiler, and
also better match the corresponding support in GNU as.

Reviewers: jvoung, eliben

Differential Revision: http://reviews.llvm.org/D5801

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219811 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:10:04 +00:00
Duncan P. N. Exon Smith
ffc65d2bfe DI: Make comments "brief"-er, NFC
Follow-up to r219801.  Post-commit review pointed out that all comments
require a `\brief` description [1], so I converted many and recrafted a
few to be briefer or to include a brief intro.  (If I'm going to clean
them up, I should do it right!)

[1]: http://llvm.org/docs/CodingStandards.html#doxygen-use-in-documentation-comments

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219808 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 17:01:28 +00:00
Sanjay Patel
5af49c83c3 Use 'auto' for easier reading; no functional change intended.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219804 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:21:37 +00:00
Sanjay Patel
ed0b7a0b1a remove function names from comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219803 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:20:45 +00:00
Duncan P. N. Exon Smith
03631a8ad5 DI: Cleanup comments, NFC
A number of comment cleanups:

  - Remove duplicated function and class names from comments.

  - Remove duplicated comments from source file (some of which were
    out-of-sync).

  - Move any unduplicated comments from source file to header.

  - Remove some noisy comments entirely (e.g., a comment for
    `DIDescriptor::print()` saying "print descriptor" just gets in the
    way of reading the code).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219801 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:15:15 +00:00
Rafael Espindola
90ce9f70e2 Simplify handling of --noexecstack by using getNonexecutableStackSection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219799 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:12:52 +00:00
Duncan P. N. Exon Smith
5c2d60d357 DI: Use a DenseMap instead of named metadata, NFC
Remove a strange round-trip through named metadata to assign preserved
local variables to their subprograms.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219798 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 16:11:41 +00:00
Rafael Espindola
b510f8d08c Move getNonexecutableStackSection up to the base ELF class.
The .note.GNU-stack section is not SystemZ/X86 specific.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219796 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 15:44:16 +00:00
Matt Arsenault
18ed4acf21 R600: Use existing variable
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219778 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 05:07:00 +00:00
Matt Arsenault
8a55ca3c41 R600: Remove outdated comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219777 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 05:06:57 +00:00
Juergen Ributzka
0081070cfd Revert "[FastISel][AArch64] Add custom lowering for GEPs."
This breaks our internal build bots. Reverting it to get the bots green again.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219776 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 04:55:48 +00:00
Jingyue Wu
75d77cd179 [MachineSink] Use the real post dominator tree
Summary:
Fixes a FIXME in MachineSinking. Instead of using the simple heuristics in
isPostDominatedBy, use the real MachinePostDominatorTree and MachineLoopInfo.
The old heuristics caused instructions to sink unnecessarily, and might create
register pressure.

This is the second try of the fix. The first one (D4814) caused a performance
regression due to failing to sink instructions out of loops (PR21115). This
patch fixes PR21115 by sinking an instruction from a deeper loop to a shallower
one regardless of whether the target block post-dominates the source.

Thanks Alexey Volkov for reporting PR21115! 

Test Plan:
Added a NVPTX codegen test to verify that our change prevents the backend from
over-sinking. It also shows the unnecessary register pressure caused by
over-sinking.

Added an X86 test to verify we can sink instructions out of loops regardless of
the dominance relationship. This test is reduced from Alexey's test in PR21115.

Updated an affected test in X86.

Also ran SPEC CINT2006 and llvm-test-suite for compilation time and runtime
performance. Results are attached separately in the review thread.

Reviewers: Jiangning, resistor, hfinkel

Reviewed By: hfinkel

Subscribers: hfinkel, bruno, volkalexey, llvm-commits, meheff, eliben, jholewinski

Differential Revision: http://reviews.llvm.org/D5633

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219773 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 03:27:43 +00:00
Tim Northover
d3458577a9 ARM: drop check for triple that's no longer used.
Early attempts to support AAPCS bare metal MachO targets based the decision on
the CPU being compiled for. This was not a particularly great idea and we've
got a better option now, but this check remained.

No functional change for any target we care about.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219767 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 01:05:01 +00:00
Eric Christopher
c6d2db4db1 Remove unused variable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219750 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-15 00:09:07 +00:00
Eric Christopher
2ff93bfec6 No need to cache this unused variable.
Patch by Ehsan Akhgari.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219749 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 23:58:51 +00:00
Gerolf Hoflehner
cd27f3fb33 [AArch64] Wrong CC access in CSINC-conditional branch sequence
This is a follow up to commit r219742. It removes the CCInMI variable
and accesses the CC in CSCINC directly. In the case of a conditional
branch accessing the CC with CCInMI was wrong.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219748 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 23:55:00 +00:00
Nick Kledzik
1a0afd82b1 [llvm-objdump] Update error message and add test case for mach-o file with bad library ordinals
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219746 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 23:29:38 +00:00
Gerolf Hoflehner
2bddd7cf65 [AAarch64] Optimize CSINC-branch sequence
Peephole optimization that generates a single conditional branch
for csinc-branch sequences like in the examples below. This is
possible when the csinc sets or clears a register based on a condition
code and the branch checks that register. Also the condition
code may not be modified between the csinc and the original branch.

Examples:

1. Convert csinc w9, wzr, wzr, <CC>;tbnz w9, #0, 0x44
   to b.<invCC>

2. Convert csinc w9, wzr, wzr, <CC>; tbz w9, #0, 0x44
   to b.<CC>


rdar://problem/18506500



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219742 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 23:07:53 +00:00
Hal Finkel
75277b9f70 [LoopVectorize] Ignore @llvm.assume for cost estimates and legality
A few minor changes to prevent @llvm.assume from interfering with loop
vectorization. First, treat @llvm.assume like the lifetime intrinsics, which
are scalarized (but don't otherwise interfere with the legality checking).
Second, ignore the cost of ephemeral instructions in the loop (these will go
away anyway during CodeGen).

Alignment assumptions and other uses of @llvm.assume can often end up inside of
loops that should be vectorized (this is not uncommon for assumptions generated
by __attribute__((align_value(n))), for example).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219741 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:59:49 +00:00
David Majnemer
3a1045d8db MC, COFF: Make bigobj test compatible with python3
No functionality change intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219739 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:35:11 +00:00
Simon Pilgrim
84a3feea38 [X86][SSE] pslldq/psrldq shuffle mask decodes
Patch to provide shuffle decodes and asm comments for the sse pslldq/psrldq SSE2/AVX2 byte shift instructions.

Differential Revision: http://reviews.llvm.org/D5598


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219738 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:31:34 +00:00
David Majnemer
b315be205c MC: Rewrite bigobj test in python
This makes the test easier to work with.  No functionality change
intended.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219737 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:26:49 +00:00
Tim Northover
7419c9c0c0 ARM: remove ARM/Thumb distinction for preferred alignment.
Thumb1 has legitimate reasons for preferring 32-bit alignment of types
i1/i8/i16, since the 16-bit encoding of "add rD, sp, #imm" requires #imm to be
a multiple of 4. However, this is a trade-off betweem code size and RAM usage;
the DataLayout string is not the best place to represent it even if desired.

So this patch removes the extra Thumb requirements, hopefully making ARM and
Thumb completely compatible in this respect.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219734 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:12:17 +00:00
Tim Northover
32d728fbb9 ARM: allow misaligned local variables in Thumb1 mode.
There's no hard requirement on LLVM to align local variable to 32-bits, so the
Thumb1 frame handling needs to be able to deal with variables that are only
naturally aligned without falling over.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219733 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 22:12:14 +00:00
David Majnemer
388c2d325a Add a test for writing COFF BigObj
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219729 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 21:47:53 +00:00
Juergen Ributzka
569c5b62af [FastISel][AArch64] Add custom lowering for GEPs.
This is mostly a copy of the existing FastISel GEP code, but on AArch64 we bail
out even for simple cases, because the standard fastEmit functions don't cover
MUL and ADD is lowered inefficientily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219726 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 21:41:23 +00:00
Hans Wennborg
76806748d4 [x86 asm] allow fwait alias in both At&t and Intel modes (PR21208)
Differential Revision: http://reviews.llvm.org/D5741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219725 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 21:41:17 +00:00
Tim Northover
eddeac0b8c ARM: set preferred aggregate alignment to 32 universally.
Before, ARM and Thumb mode code had different preferred alignments, which could
lead to some rather unexpected results. There's justification for reducing it
from the default 64-bits (wasted space), but I don't think there is for going
below 32-bits.

There's no actual ABI change here, just to reassure people.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219719 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 20:57:26 +00:00
Hal Finkel
2a77e6bdd1 [CFL-AA] CFL-AA should not assert on an va_arg instruction
The CFL-AA implementation was missing a visit* routine for va_arg instructions,
causing it to assert when run on a function that had one. For now, handle these
in a conservative way.

Fixes PR20954.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219718 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 20:51:26 +00:00
Sanjay Patel
3f349b2ba8 Optimize away fabs() calls when input is squared (known positive).
Eliminate library calls and intrinsic calls to fabs when the input 
is a squared value.

Note that no unsafe-math / fast-math assumptions are needed for
this optimization.

Differential Revision: http://reviews.llvm.org/D5777



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@219717 91177308-0d34-0410-b5e6-96231b3b80d8
2014-10-14 20:43:11 +00:00