Commit Graph

307 Commits

Author SHA1 Message Date
Simon Pilgrim ad403a483a [X86] This bit-test TODO has been moved in PR36551
llvm-svn: 326658
2018-03-03 16:31:17 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
As part of the unification of the debug format and the MIR format, print
MBB references as '%bb.5'.

The MIR printer prints the IR name of a MBB only for block definitions.

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g'
* find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g'
* grep -nr 'BB#' and fix

Differential Revision: https://reviews.llvm.org/D40422

llvm-svn: 319665
2017-12-04 17:18:51 +00:00
Roman Shirokiy d93998f606 Test commit
llvm-svn: 272393
2016-06-10 13:12:48 +00:00
Robin Morisset d780781b1f [X86] Erase some obsolete comments from README.txt
I just tried reproducing some of the optimization failures in README.txt in the
X86 backend, and many of them could not be reproduced. In general the entire
file appears quite bit-rotted, whatever interesting parts remain should be
moved to bugzilla, and the rest deleted. I did not spend the time to do that,
so I just deleted the few I tried reproducing which are obsolete, to save some
time to whoever will find the courage to do it.

llvm-svn: 218170
2014-09-19 23:56:46 +00:00
Manuel Jacob a7c48f99ae CodeGenPrep: sink extends of illegal types into use block.
Summary:
This helps the instruction selector to lower an i64 * i64 -> i128
multiplication into a single instruction on targets which support it.

This is an update of D2973 which was reverted because of a bug reported
as PR19084.

Reviewers: t.p.northover, chapuni

Reviewed By: t.p.northover

CC: llvm-commits, alex, chapuni

Differential Revision: http://llvm-reviews.chandlerc.com/D3021

llvm-svn: 203797
2014-03-13 13:36:25 +00:00
NAKAMURA Takumi 1783e1e984 Revert r203230, "CodeGenPrep: sink extends of illegal types into use block."
It choked i686 stage2.

llvm-svn: 203386
2014-03-09 11:01:07 +00:00
Tim Northover ad3d81d320 CodeGenPrep: sink extends of illegal types into use block.
This helps the instruction selector to lower an i64 * i64 -> i128
multiplication into a single instruction on targets which support it.

Patch by Manuel Jacob.

llvm-svn: 203230
2014-03-07 11:04:30 +00:00
Alp Toker 171b0c36a3 Fix documentation typos
llvm-svn: 197757
2013-12-20 00:33:39 +00:00
Andrey Churbanov 3535e04483 Checking commit access; removed one space added in previous test checkin by Jim
llvm-svn: 189673
2013-08-30 14:40:24 +00:00
Jim Cownie b09bb1ce19 Checking commit access; added one space
llvm-svn: 189111
2013-08-23 15:51:37 +00:00
Paul Redmond 5917f4c715 Transform (x&C)>V into (x&C)!=0 where possible
When the least bit of C is greater than V, (x&C) must be greater than V
if it is not zero, so the comparison can be simplified.

Although this was suggested in Target/X86/README.txt, it benefits any
architecture with a directly testable form of AND.

Patch by Kevin Schoedel

llvm-svn: 170576
2012-12-19 19:47:13 +00:00
Benjamin Kramer 88d31b3f0c Add a note about a missed cmov -> sbb opportunity.
llvm-svn: 153741
2012-03-30 13:02:58 +00:00
Craig Topper f210619d08 Fix typo in the X86 backend readme. Patch from Jaeden Amero.
llvm-svn: 147739
2012-01-07 20:35:21 +00:00
Benjamin Kramer 767bbe48c1 Chandler fixed this.
llvm-svn: 147247
2011-12-24 11:23:32 +00:00
Lang Hames de7ab801cc Add a natural stack alignment field to TargetData, and prevent InstCombine from
promoting allocas to preferred alignments that exceed the natural
alignment. This avoids some potentially expensive dynamic stack realignments.

The natural stack alignment is set in target data strings via the "S<size>"
option. Size is in bits and must be a multiple of 8. The natural stack alignment
defaults to "unspecified" (represented by a zero value), and the "unspecified"
value does not prevent any alignment promotions. Target maintainers that care
about avoiding promotions should explicitly add the "S<size>" option to their
target data strings.

llvm-svn: 141599
2011-10-10 23:42:08 +00:00
Benjamin Kramer 42c0330a79 X86: Add patterns for the movbe instruction (mov + bswap, only available on atom)
llvm-svn: 141563
2011-10-10 18:34:56 +00:00
Benjamin Kramer 124ac2b997 Add a neat little two's complement hack for x86.
On x86 we can't encode an immediate LHS of a sub directly. If the RHS comes from a XOR with a constant we can
fold the negation into the xor and add one to the immediate of the sub. Then we can turn the sub into an add,
which can be commuted and encoded efficiently.

This code is generated for __builtin_clz and friends.

llvm-svn: 136167
2011-07-26 22:42:13 +00:00
Benjamin Kramer c956033947 Add a note about efficient codegen for binary log.
llvm-svn: 135996
2011-07-25 22:30:00 +00:00
Chris Lattner 1e81f57bf0 add a note
llvm-svn: 131455
2011-05-17 07:22:33 +00:00
Benjamin Kramer 6708499b6d This is done.
llvm-svn: 130499
2011-04-29 14:09:57 +00:00
Chris Lattner 2a75c72e1c move PR9803 to this readme.
llvm-svn: 130385
2011-04-28 05:33:16 +00:00
Eli Friedman 55f7bf3289 Remove working entry from README.
llvm-svn: 129654
2011-04-17 02:36:27 +00:00
Chris Lattner 0ab5e2cded Fix a ton of comment typos found by codespell. Patch by
Luis Felipe Strano Moraes!

llvm-svn: 129558
2011-04-15 05:18:47 +00:00
Chris Lattner 6f195469b1 move PR9661 out to here.
llvm-svn: 129527
2011-04-14 18:47:18 +00:00
Rafael Espindola b4dd95b4f9 Add another case we are not optimizing.
llvm-svn: 129012
2011-04-06 17:35:32 +00:00
Rafael Espindola 7a3b244d45 The original issue has been fixed by not doing unnecessary sign extensions.
Change the test to force a sign extension and expose the problem again.

llvm-svn: 129011
2011-04-06 17:19:35 +00:00
Eli Friedman e8f2be0c10 A couple new README entries.
llvm-svn: 127786
2011-03-17 01:22:09 +00:00
Chris Lattner 5237febf0c a serious "compare CSE" issue that is nontrivial to get right,
but which is responsible for us doing really bad things to 256.bzip2.

llvm-svn: 126126
2011-02-21 17:03:47 +00:00
Cameron Zwarich 39314bdbc8 A lo/hi mul has higher latency than an imul r,ri, e.g. 5 cycles compared to 3
on Core 2 and Nehalem, so the code we generate is better than GCC's here.

llvm-svn: 126100
2011-02-21 01:29:32 +00:00
Cameron Zwarich 8731d0cc83 The signed version of our "magic number" computation for the integer approximation
of a constant had a minor typo introduced when copying it from the book, which
caused it to favor negative approximations over positive approximations in many
cases. Positive approximations require fewer operations beyond the multiplication.

In the case of division by 3, we still generate code that is a single instruction
larger than GCC's code.

llvm-svn: 126097
2011-02-21 00:22:02 +00:00
Eli Friedman 78b9851a3a Minor x86 README updates.
llvm-svn: 126054
2011-02-19 21:54:28 +00:00
Chris Lattner 0281731cc2 add a poor division by constant case.
llvm-svn: 125832
2011-02-18 05:35:49 +00:00
Chris Lattner 51415d26f1 update a bunch of entries.
llvm-svn: 122700
2011-01-02 18:31:38 +00:00
Chris Lattner f9e0a56b94 fix some sort of weird pasto
llvm-svn: 122560
2010-12-26 12:05:11 +00:00
Chris Lattner 424de3498b add a note
llvm-svn: 122559
2010-12-26 03:53:31 +00:00
Benjamin Kramer b37ae33125 Remove some obsolete README items, add a new one off the top of my head.
llvm-svn: 122495
2010-12-23 15:07:02 +00:00
Benjamin Kramer 6020ed9d99 X86: Lower a select directly to a setcc_carry if possible.
int test(unsigned long a, unsigned long b) { return -(a < b); }
compiles to
  _test:                              ## @test
    cmpq  %rsi, %rdi                  ## encoding: [0x48,0x39,0xf7]
    sbbl  %eax, %eax                  ## encoding: [0x19,0xc0]
    ret                               ## encoding: [0xc3]
instead of
  _test:                              ## @test
    xorl  %ecx, %ecx                  ## encoding: [0x31,0xc9]
    cmpq  %rsi, %rdi                  ## encoding: [0x48,0x39,0xf7]
    movl  $-1, %eax                   ## encoding: [0xb8,0xff,0xff,0xff,0xff]
    cmovael %ecx, %eax                ## encoding: [0x0f,0x43,0xc1]
    ret                               ## encoding: [0xc3]

llvm-svn: 122451
2010-12-22 23:09:28 +00:00
Benjamin Kramer c8b035d006 Factor the (x & 2^n) ? 2^m : 0 instcombine into its own method and generalize it
to catch cases where n != m with a shift.

llvm-svn: 121608
2010-12-11 09:42:59 +00:00
Evan Cheng d4b0873c06 Enable sibling call optimization of libcalls which are expanded during
legalization time. Since at legalization time there is no mapping from
SDNode back to the corresponding LLVM instruction and the return
SDNode is target specific, this requires a target hook to check for
eligibility. Only x86 and ARM support this form of sibcall optimization
right now.
rdar://8707777

llvm-svn: 120501
2010-11-30 23:55:39 +00:00
Chris Lattner 5d2262dc76 apparently tailcalls are better on darwin/x86-64 than on linux?
llvm-svn: 119947
2010-11-21 18:59:20 +00:00
Dan Gohman 3c9b5f394b Don't narrow the load and store in a load+twiddle+store sequence unless
there are clearly no stores between the load and the store. This fixes
this miscompile reported as PR7833.

This breaks the test/CodeGen/X86/narrow_op-2.ll optimization, which is
safe, but awkward to prove safe. Move it to X86's README.txt.

llvm-svn: 112861
2010-09-02 21:18:42 +00:00
Eli Friedman f75de6eae7 A couple of small missed optimizations.
llvm-svn: 112411
2010-08-29 05:07:40 +00:00
Eric Christopher 9a77382685 Custom lower the memory barrier instructions and add support
for lowering without sse2.  Add a couple of new testcases.

Fixes a few libgomp tests and latent bugs.  Remove a few todos.

llvm-svn: 109078
2010-07-22 02:48:34 +00:00
Eli Friedman 1f41303260 Remove a fixed item, update a couple partially-fixed items.
llvm-svn: 105375
2010-06-03 01:01:48 +00:00
Dan Gohman 312d604ee2 This is now done.
llvm-svn: 97450
2010-03-01 17:43:57 +00:00
Eli Friedman 4d4c6944e9 A few missed optimizations; the last one could have a significant impact on
code with lots of bitfields.

llvm-svn: 95809
2010-02-10 21:26:04 +00:00
Chris Lattner 3eb76c23dd this is an SSE-specific issue.
llvm-svn: 93373
2010-01-13 23:29:11 +00:00
Chris Lattner fb534d97b5 X86 if conversion + tail merging issues from PR6032.
llvm-svn: 93372
2010-01-13 23:28:40 +00:00
Dan Gohman 5d1987f9a0 Remove some README.txt entries which are now implemented.
llvm-svn: 92511
2010-01-04 20:55:05 +00:00
Eli Friedman dbe2aa91b9 A couple minor README updates.
llvm-svn: 91823
2009-12-21 08:03:16 +00:00