Commit Graph

76 Commits

Author SHA1 Message Date
Benjamin Kramer
8118c94a55 Add a note for -ffast-math optimization of vector norm.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153031 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-19 00:43:34 +00:00
Benjamin Kramer
bf67a99c35 This is now implemented.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146258 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-09 15:45:57 +00:00
Lang Hames
bb5b3f3359 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.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141599 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-10 23:42:08 +00:00
Benjamin Kramer
d800cf0a50 Add a note about SSE4.1 roundss/roundsd.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125438 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-12 17:58:16 +00:00
Chris Lattner
f0f5780b39 update this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113116 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-05 20:22:09 +00:00
Chris Lattner
1a68958d3d we should pattern match the SSE complex arithmetic ops.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112109 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-25 23:31:42 +00:00
Chris Lattner
b7f243a638 random improvement for variable shift codegen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111813 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-23 17:30:29 +00:00
Jakob Stoklund Olesen
aef48d7b36 Remove obsolete README_SSE note.
We are generating movaps for all XMM register copies, including scalar
floating point values. This is known to be at least as good as movss and movsd
for all known architectures up to and including Nehalem because it avoids a
partial register stall.

The SSEDomainFix pass will switch movaps to movdqa when appropriate (i.e., when
operands come from the integer unit). We don't now that switching movaps to
movapd has any benefit.

The same applies to andps -> pand.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108096 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-11 17:13:42 +00:00
Chris Lattner
c06cbad141 some notes about suboptimal insertps's
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107613 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-05 05:48:41 +00:00
Eli Friedman
db1bf34178 Remove some already-fixed README entries.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105377 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-03 01:47:31 +00:00
Eli Friedman
a04a2c0a50 Remove README entry which no longer compiles to something sane.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@105376 91177308-0d34-0410-b5e6-96231b3b80d8
2010-06-03 01:16:51 +00:00
Dan Gohman
a9445e11c5 Floating-point add, sub, and mul are now spelled fadd, fsub, and fmul,
respectively.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@97531 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-02 01:11:08 +00:00
Dan Gohman
f451cb870e Fix "the the" and similar typos.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95781 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-10 16:03:48 +00:00
Chris Lattner
1728472726 add a note from PR6194
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95649 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-09 05:45:29 +00:00
Chris Lattner
7db21bdb7d move the PR6214 microoptzn to this file.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95299 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-04 07:32:01 +00:00
Chris Lattner
5350f78323 this is an SSE-specific issue.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93373 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-13 23:29:11 +00:00
Chris Lattner
e6c1473e56 Bill implemented this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63752 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04 19:09:07 +00:00
Chris Lattner
8dfdf5d62d add a note, this is why we're faster at SciMark-MonteCarlo with
SSE disabled.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63751 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-04 19:08:01 +00:00
Evan Cheng
1632782fe9 The memory alignment requirement on some of the mov{h|l}p{d|s} patterns are 16-byte. That is overly strict. These instructions read / write f64 memory locations without alignment requirement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63195 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-28 08:35:02 +00:00
Chris Lattner
e306b3d0d9 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56391 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-20 19:17:53 +00:00
Chris Lattner
fa7e17d379 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@54964 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-19 00:41:02 +00:00
Evan Cheng
ab26227c8c - Fix a x86 vector isel bug: illegal transformation of a vector_shuffle into a
shift.
- Add a readme entry for a missing vector_shuffle optimization that results in
  awful codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52740 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-25 20:52:59 +00:00
Evan Cheng
fe5b159ae2 This is done.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51526 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-24 00:10:13 +00:00
Evan Cheng
cd0baf21a1 Use movlps / movhps to modify low / high half of 16-byet memory location.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51501 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 21:23:16 +00:00
Dan Gohman
a9e75631a7 Elaborate on the entry on integer vector multiplication by constants.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51491 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 18:05:39 +00:00
Evan Cheng
d4083d01d2 New entry.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51487 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 17:28:11 +00:00
Chris Lattner
3adaa93700 we compile multiply-by-constant into horrible code. Doesn't sse4 have some
instruction for doing this?


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51473 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-23 04:29:53 +00:00
Chris Lattner
3b34e1e9e8 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51062 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 19:56:20 +00:00
Chris Lattner
7171c836a9 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51060 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 18:48:54 +00:00
Evan Cheng
77f0b7a50a Instead of a vector load, shuffle and then extract an element. Load the element from address with an offset.
pshufd $1, (%rdi), %xmm0
        movd %xmm0, %eax
=>
        movl 4(%rdi), %eax


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51026 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 08:35:03 +00:00
Evan Cheng
fa7fd33a26 On x86, it's safe to treat i32 load anyext as a normal i32 load. Ditto for i8 anyext load to i16.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51019 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 00:54:02 +00:00
Evan Cheng
9bfa03c6fd Xform bitconvert(build_pair(load a, load b)) to a single load if the load locations are at the right offset from each other.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51008 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-12 23:04:07 +00:00
Anton Korobeynikov
64d69102a1 Add note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@50959 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-11 14:33:15 +00:00
Chris Lattner
2189c17443 add a note, this is actually not too bad to implement.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49466 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-10 05:54:50 +00:00
Chris Lattner
a825d75f1d move the x86-32 part of PR2108 here.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49465 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-10 05:37:47 +00:00
Chris Lattner
67f453aae7 Finish implementing a readme entry: when inserting an i64 variable
into a vector of zeros or undef, and when the top part is obviously
zero, we can just use movd + shuffle.  This allows us to compile
vec_set-B.ll into:

_test3:
	movl	$1234567, %eax
	andl	4(%esp), %eax
	movd	%eax, %xmm0
	ret

instead of:

_test3:
	subl	$28, %esp
	movl	$1234567, %eax
	andl	32(%esp), %eax
	movl	%eax, (%esp)
	movl	$0, 4(%esp)
	movq	(%esp), %xmm0
	addl	$28, %esp
	ret



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48090 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-09 05:42:06 +00:00
Chris Lattner
f68cbceb17 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48064 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-09 01:08:22 +00:00
Chris Lattner
62098040a1 Implement a readme entry, compiling
#include <xmmintrin.h>
__m128i doload64(short x) {return _mm_set_epi16(0,0,0,0,0,0,0,1);}

into:
	movl	$1, %eax
	movd	%eax, %xmm0
	ret

instead of a constant pool load.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48063 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-09 01:05:04 +00:00
Chris Lattner
b607f9c822 This one looks easy, add a note.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48055 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-08 22:32:39 +00:00
Chris Lattner
f658ad10f6 move these to the appropriate file
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48054 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-08 22:28:45 +00:00
Chris Lattner
4d93b2f16d evan implemented this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47948 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-05 17:11:51 +00:00
Chris Lattner
063d825208 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47939 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-05 07:22:39 +00:00
Chris Lattner
767486b1d5 Evan implemented these.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47828 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-02 18:05:14 +00:00
Chris Lattner
eb05f90c71 upgrade some entries, remove stuff that is done.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47109 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-14 06:19:02 +00:00
Nate Begeman
b5041b3085 readme updates
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47051 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 07:06:12 +00:00
Nate Begeman
14d12caf1d Enable SSE4 codegen and pattern matching.
Add some notes to the README.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46949 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-11 04:19:36 +00:00
Chris Lattner
f6b935d8e6 add a note
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46413 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-27 07:31:41 +00:00
Chris Lattner
4d53049c92 Add some notes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46405 91177308-0d34-0410-b5e6-96231b3b80d8
2008-01-26 20:12:07 +00:00
Chris Lattner
03c079d5fc One readme entry is done, one is really easy (Evan, want to investigate
eliminating the llvm.x86.sse2.loadl.pd intrinsic?), one shuffle optzn
may be done (if shufps is better than pinsw, Evan, please review), and
we already know about LICM of simple instructions.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45407 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29 19:31:47 +00:00
Evan Cheng
0b0102b172 New entry.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45280 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-21 01:31:58 +00:00