Commit Graph

81 Commits

Author SHA1 Message Date
Benjamin Kramer 3d0031e0b8 Remove outdated README-SSE.txt entries.
llvm-svn: 233292
2015-03-26 17:12:16 +00:00
Jim Grosbach e9008de652 X86: Resolve a long standing FIXME and properly isel pextr[bw].
Generalize the AArch64 .td nodes for AssertZext and AssertSext. Use
them to match the relevant pextr store instructions.

The test widen_load-2.ll requires a slight change because with the
stores gone, the remaining instructions are scheduled in a different
order.

Add test cases for SSE4 and AVX variants.

Resolves rdar://13414672.

Patch by Adam Nemet <anemet@apple.com>.

llvm-svn: 200957
2014-02-07 00:16:33 +00:00
Benjamin Kramer 5bc180c14f X86: Turn fp selects into mask operations.
double test(double a, double b, double c, double d) { return a<b ? c : d; }

before:
_test:
	ucomisd	%xmm0, %xmm1
	ja	LBB0_2
	movaps	%xmm3, %xmm2
LBB0_2:
	movaps	%xmm2, %xmm0

after:
_test:
	cmpltsd	%xmm1, %xmm0
	andpd	%xmm0, %xmm2
	andnpd	%xmm3, %xmm0
	orpd	%xmm2, %xmm0

Small speedup on Benchmarks/SmallPT

llvm-svn: 187706
2013-08-04 12:05:16 +00:00
Benjamin Kramer 189fc5819a X86: Add a note.
llvm-svn: 175408
2013-02-17 23:34:14 +00:00
Chris Lattner ba3ba8fa1f some peepholes that should match horizontal add/sub operations.
llvm-svn: 163103
2012-09-03 02:58:21 +00:00
Benjamin Kramer 57003a6768 Add a note for -ffast-math optimization of vector norm.
llvm-svn: 153031
2012-03-19 00:43:34 +00:00
Benjamin Kramer 863683c590 This is now implemented.
llvm-svn: 146258
2011-12-09 15:45:57 +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 69affe6a94 Add a note about SSE4.1 roundss/roundsd.
llvm-svn: 125438
2011-02-12 17:58:16 +00:00
Chris Lattner 5cac0f71ca update this.
llvm-svn: 113116
2010-09-05 20:22:09 +00:00
Chris Lattner aecf47a5cb we should pattern match the SSE complex arithmetic ops.
llvm-svn: 112109
2010-08-25 23:31:42 +00:00
Chris Lattner a42202e0e4 random improvement for variable shift codegen.
llvm-svn: 111813
2010-08-23 17:30:29 +00:00
Jakob Stoklund Olesen 98ee37d878 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.

llvm-svn: 108096
2010-07-11 17:13:42 +00:00
Chris Lattner 7b909ac785 some notes about suboptimal insertps's
llvm-svn: 107613
2010-07-05 05:48:41 +00:00
Eli Friedman ceb13f2af3 Remove some already-fixed README entries.
llvm-svn: 105377
2010-06-03 01:47:31 +00:00
Eli Friedman a59b7a72b9 Remove README entry which no longer compiles to something sane.
llvm-svn: 105376
2010-06-03 01:16:51 +00:00
Dan Gohman 6f34abd092 Floating-point add, sub, and mul are now spelled fadd, fsub, and fmul,
respectively.

llvm-svn: 97531
2010-03-02 01:11:08 +00:00
Dan Gohman 4a618827de Fix "the the" and similar typos.
llvm-svn: 95781
2010-02-10 16:03:48 +00:00
Chris Lattner cf11e602a2 add a note from PR6194
llvm-svn: 95649
2010-02-09 05:45:29 +00:00
Chris Lattner fb5670fc16 move the PR6214 microoptzn to this file.
llvm-svn: 95299
2010-02-04 07:32:01 +00:00
Chris Lattner 3eb76c23dd this is an SSE-specific issue.
llvm-svn: 93373
2010-01-13 23:29:11 +00:00
Chris Lattner e84a7911c4 Bill implemented this.
llvm-svn: 63752
2009-02-04 19:09:07 +00:00
Chris Lattner 553fd7e1eb add a note, this is why we're faster at SciMark-MonteCarlo with
SSE disabled.

llvm-svn: 63751
2009-02-04 19:08:01 +00:00
Evan Cheng f31f288863 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.
llvm-svn: 63195
2009-01-28 08:35:02 +00:00
Chris Lattner 9a8eb0d534 add a note
llvm-svn: 56391
2008-09-20 19:17:53 +00:00
Chris Lattner f076d5eea8 add a note
llvm-svn: 54964
2008-08-19 00:41:02 +00:00
Evan Cheng 3fc2372d3a - 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.

llvm-svn: 52740
2008-06-25 20:52:59 +00:00
Evan Cheng 8647b875cc This is done.
llvm-svn: 51526
2008-05-24 00:10:13 +00:00
Evan Cheng 04d24edcbb Use movlps / movhps to modify low / high half of 16-byet memory location.
llvm-svn: 51501
2008-05-23 21:23:16 +00:00
Dan Gohman 66eea1b9b3 Elaborate on the entry on integer vector multiplication by constants.
llvm-svn: 51491
2008-05-23 18:05:39 +00:00
Evan Cheng d25cb8e0d2 New entry.
llvm-svn: 51487
2008-05-23 17:28:11 +00:00
Chris Lattner 3546c2b4e4 we compile multiply-by-constant into horrible code. Doesn't sse4 have some
instruction for doing this?

llvm-svn: 51473
2008-05-23 04:29:53 +00:00
Chris Lattner 03ce206143 add a note
llvm-svn: 51062
2008-05-13 19:56:20 +00:00
Chris Lattner d17f58ae6e add a note
llvm-svn: 51060
2008-05-13 18:48:54 +00:00
Evan Cheng 1120279ae6 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

llvm-svn: 51026
2008-05-13 08:35:03 +00:00
Evan Cheng 3f40c69083 On x86, it's safe to treat i32 load anyext as a normal i32 load. Ditto for i8 anyext load to i16.
llvm-svn: 51019
2008-05-13 00:54:02 +00:00
Evan Cheng b980f6fb3d Xform bitconvert(build_pair(load a, load b)) to a single load if the load locations are at the right offset from each other.
llvm-svn: 51008
2008-05-12 23:04:07 +00:00
Anton Korobeynikov a38e72d247 Add note
llvm-svn: 50959
2008-05-11 14:33:15 +00:00
Chris Lattner aeb23a8a34 add a note, this is actually not too bad to implement.
llvm-svn: 49466
2008-04-10 05:54:50 +00:00
Chris Lattner c692188075 move the x86-32 part of PR2108 here.
llvm-svn: 49465
2008-04-10 05:37:47 +00:00
Chris Lattner b6387c8a74 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

llvm-svn: 48090
2008-03-09 05:42:06 +00:00
Chris Lattner 93930dc28c add a note
llvm-svn: 48064
2008-03-09 01:08:22 +00:00
Chris Lattner eef374c197 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.

llvm-svn: 48063
2008-03-09 01:05:04 +00:00
Chris Lattner 35adf46967 This one looks easy, add a note.
llvm-svn: 48055
2008-03-08 22:32:39 +00:00
Chris Lattner a76e23a935 move these to the appropriate file
llvm-svn: 48054
2008-03-08 22:28:45 +00:00
Chris Lattner 7c08a01698 evan implemented this.
llvm-svn: 47948
2008-03-05 17:11:51 +00:00
Chris Lattner 2acd0c25f6 add a note
llvm-svn: 47939
2008-03-05 07:22:39 +00:00
Chris Lattner a70df9e2ee Evan implemented these.
llvm-svn: 47828
2008-03-02 18:05:14 +00:00
Chris Lattner eb63b09206 upgrade some entries, remove stuff that is done.
llvm-svn: 47109
2008-02-14 06:19:02 +00:00
Nate Begeman eea32990a9 readme updates
llvm-svn: 47051
2008-02-13 07:06:12 +00:00