180 Commits

Author SHA1 Message Date
Sam Parker
214f7bf5cc Enable simplify libcalls for ARM PCS
Teach SimplifyLibcalls that in can treat functions annotated with
apcs, aapcs or aapcs_vfp like normal C functions if they only take
and return integer or pointer values, and the target is not iOS.

Differential Revision: https://reviews.llvm.org/D24453

llvm-svn: 281322
2016-09-13 12:10:14 +00:00
David Majnemer
0a16c22846 Use range algorithms instead of unpacking begin/end
No functionality change is intended.

llvm-svn: 278417
2016-08-11 21:15:00 +00:00
Davide Italiano
873219c406 [SimplifyLibCalls] Restore the old behaviour, emit a libcall.
Hal pointed out that the semantic of our intrinsic and the libc
call are slightly different. Add a comment while I'm here to
explain why we can't emit an intrinsic. Thanks Hal!

llvm-svn: 278200
2016-08-10 06:33:32 +00:00
Davide Italiano
e3b916d164 [SimplifyLibCalls] Emit sqrt intrinsic instead of a libcall.
llvm-svn: 277972
2016-08-08 03:23:01 +00:00
Davide Italiano
27da131f32 [SLC] Emit an intrinsic instead of a libcall for pow.
Differential Revision:  https://reviews.llvm.org/D22104

llvm-svn: 277963
2016-08-07 20:27:03 +00:00
Sjoerd Meijer
7435a910b5 Addressing post-commit comments for not rewriting fputs:
moved the optimise for size check inside function optimizeFPuts.

llvm-svn: 274758
2016-07-07 14:31:19 +00:00
Sjoerd Meijer
17c08dc701 Code size optimisation: don't rewrite fputs to fwrite when optimising for size
because fwrite requires more arguments and thus extra MOVs are required.

llvm-svn: 274753
2016-07-07 13:56:23 +00:00
Joerg Sonnenberger
8ffe7ab7c2 Optimize a printf with a double procent to putchar.
llvm-svn: 268922
2016-05-09 14:36:16 +00:00
Ahmed Bougacha
d765a82b54 [TLI] Unify LibFunc signature checking. NFCI.
I tried to be as close as possible to the strongest check that
existed before; cleaning these up properly is left for future work.

Differential Revision: http://reviews.llvm.org/D19469

llvm-svn: 267758
2016-04-27 19:04:35 +00:00
David Majnemer
abb9f55c80 Revert "[SimplifyLibCalls] sprintf doesn't copy null bytes"
The destination buffer that sprintf uses is restrict qualified, we do
not need to worry about derived pointers referenced via format
specifiers.

This reverts commit r267580.

llvm-svn: 267605
2016-04-26 21:04:47 +00:00
David Majnemer
8cd77baebc [SimplifyLibCalls] sprintf doesn't copy null bytes
sprintf doesn't read or copy the terminating null byte from it's string
operands.  sprintf will append it's own after processing all of the
format specifiers.

This fixes PR27526.

llvm-svn: 267580
2016-04-26 18:16:49 +00:00
Mehdi Amini
b550cb1750 [NFC] Header cleanup
Removed some unused headers, replaced some headers with forward class declarations.

Found using simple scripts like this one:
clear && ack --cpp -l '#include "llvm/ADT/IndexedMap.h"' | xargs grep -L 'IndexedMap[<]' | xargs grep -n --color=auto 'IndexedMap'

Patch by Eugene Kosov <claprix@yandex.ru>

Differential Revision: http://reviews.llvm.org/D19219

From: Mehdi Amini <mehdi.amini@apple.com>
llvm-svn: 266595
2016-04-18 09:17:29 +00:00
David L Kreitzer
752c1448fe Simplify strlen to a subtraction for certain cases.
Patch by Li Huang (li1.huang@intel.com)

Differential Revision: http://reviews.llvm.org/D18230

llvm-svn: 266200
2016-04-13 14:31:06 +00:00
Davide Italiano
d4f5a059e0 [SimplifyLibCalls] Garbage collect dead code.
We already skip optimizations if the return value
of printf() is used, so CI->use_empty() is always
true.

Differential Revision:  http://reviews.llvm.org/D18656

llvm-svn: 265253
2016-04-03 01:46:52 +00:00
Davide Italiano
6db1dcbf6b [SimplifyLibCalls] Transform printf("%s", "a") -> putchar('a').
llvm-svn: 264588
2016-03-28 15:54:01 +00:00
David Majnemer
abae6b588b [SimplifyLibCalls] Only consider sinpi/cospi functions within the same function
The sinpi/cospi can be replaced with sincospi to remove unnecessary
computations.  However, we need to make sure that the calls are within
the same function!

This fixes PR26993.

llvm-svn: 263875
2016-03-19 04:53:02 +00:00
Sanjay Patel
980b280f50 [LibCallSimplifier] fold memset(malloc(x), 0, x) --> calloc(1, x)
This is a step towards solving PR25892:
https://llvm.org/bugs/show_bug.cgi?id=25892

It won't handle the reported case. As noted by the 'TODO' comments in the patch, 
we need to relax the hasOneUse() constraint and also match patterns that include
memset_chk() and the llvm.memset() intrinsic in addition to memset().

Differential Revision: http://reviews.llvm.org/D16337

llvm-svn: 258816
2016-01-26 16:17:24 +00:00
Sanjay Patel
577472141c move function definitions so we don't need separate declarations ; NFCI
llvm-svn: 258455
2016-01-21 23:38:43 +00:00
Sanjay Patel
9beec21fcf [LibCallSimplifier] refactor FP function signature checks ; NFCI
Use the helper function added in r258428.

The check should really be hoisted to the caller of all of these
optimize* functions, but that's another step.

llvm-svn: 258446
2016-01-21 22:58:01 +00:00
Sanjay Patel
042aed90ab avoid variable shadowing; NFC
llvm-svn: 258445
2016-01-21 22:41:16 +00:00
Sanjay Patel
0e603fc3a7 remove unnecessary variable; NFC
llvm-svn: 258444
2016-01-21 22:31:18 +00:00
Sanjay Patel
fcc7c1a0ba [LibCallSimplifier] don't get fooled by a fake fmin()
This is similar to the bug/fix:
https://llvm.org/bugs/show_bug.cgi?id=26211
http://reviews.llvm.org/rL258325

The fmin() test case reveals another bug caused by sloppy
code duplication. It will crash without this patch because
fp128 is a valid floating-point type, but we would think
that we had matched a function that used doubles.

The new helper function can be used to replace similar
checks that are used in several other places in this file.

llvm-svn: 258428
2016-01-21 20:19:54 +00:00
Sanjay Patel
4e971da272 make helper functions static; NFCI
llvm-svn: 258416
2016-01-21 18:01:57 +00:00
Sanjay Patel
bd2dc67142 [LibCallSimplifier] don't get fooled by a fake sqrt()
The test case will crash without this patch because the subsequent call to
hasUnsafeAlgebra() assumes that the call instruction is an FPMathOperator
(ie, returns an FP type).

This part of the function signature check was omitted for the sqrt() case, 
but seems to be in place for all other transforms.

Before:
http://reviews.llvm.org/rL257400
...we would have needlessly continued execution in optimizeSqrt(), but the
bug was harmless because we'd eventually fail some other check and return
without damage.

This should fix:
https://llvm.org/bugs/show_bug.cgi?id=26211

Differential Revision: http://reviews.llvm.org/D16198

llvm-svn: 258325
2016-01-20 17:41:14 +00:00
Sanjay Patel
d3112a5bcc function names start with a lowercase letter; NFC
Note: There are no uses of these functions outside of
SimplifyLibCalls, so they could be static functions in
that file.

llvm-svn: 258172
2016-01-19 19:46:10 +00:00
Sanjay Patel
d1f4f03f5e [LibCallSimplifier] use instruction-level fast-math-flags to shrink calls
This is a continuation of adding FMF to call instructions:
http://reviews.llvm.org/rL255555

llvm-svn: 258158
2016-01-19 18:38:52 +00:00
Sanjay Patel
81a63cd11f [LibCallSimplifier] use instruction-level fast-math-flags to transform pow(x, [small integer]) calls
This is a continuation of adding FMF to call instructions:
http://reviews.llvm.org/rL255555

As with D15937, the intent of the patch is to preserve the current behavior of the transform
except that we use the pow call's 'fast' attribute as a trigger rather than a function-level
attribute.

The TODO comment notes a potential follow-on patch that would propagate FMF to the new
instructions.

Differential Revision: http://reviews.llvm.org/D16122

llvm-svn: 258153
2016-01-19 18:15:12 +00:00
Sanjay Patel
53ba88dbb0 [LibCallSimplifier] use instruction-level fast-math-flags to transform pow(x, 0.5) calls
Also, propagate the FMF to the newly created sqrt() call.

llvm-svn: 257503
2016-01-12 19:06:35 +00:00
Sanjay Patel
a252815bc1 function names start with a lower case letter ; NFC
llvm-svn: 257496
2016-01-12 18:03:37 +00:00
Sanjay Patel
6002e78a06 [LibCallSimplifier] use instruction-level fast-math-flags to transform pow(exp(x)) calls
See also:
http://reviews.llvm.org/rL255555
http://reviews.llvm.org/rL256871
http://reviews.llvm.org/rL256964
http://reviews.llvm.org/rL257400
http://reviews.llvm.org/rL257404
http://reviews.llvm.org/rL257414

llvm-svn: 257491
2016-01-12 17:30:37 +00:00
Sanjay Patel
e896ede7f1 [LibCallSimplifier] use instruction-level fast-math-flags to transform log calls
Also, add tests to verify that we're checking 'fast' on both calls of each transform pair,
tighten the CHECK lines, and give the tests more meaningful names.

This is a continuation of:
http://reviews.llvm.org/rL255555
http://reviews.llvm.org/rL256871
http://reviews.llvm.org/rL256964
http://reviews.llvm.org/rL257400
http://reviews.llvm.org/rL257404

llvm-svn: 257414
2016-01-11 23:31:48 +00:00
Sanjay Patel
6c1ddbb7b6 [LibCallSimplifier] don't allow sqrt transform unless all ops are unsafe
Fix the FIXME added with:
http://reviews.llvm.org/rL257400

llvm-svn: 257404
2016-01-11 22:50:36 +00:00
Sanjay Patel
9f67dadea2 more space; NFC
llvm-svn: 257401
2016-01-11 22:35:39 +00:00
Sanjay Patel
683f29735f [LibCallSimplifier] use instruction-level fast-math-flags to transform sqrt calls
This is a continuation of adding FMF to call instructions:
http://reviews.llvm.org/rL255555

The intent of the patch is to preserve the current behavior of the transform except
that we use the sqrt instruction's 'fast' attribute as a trigger rather than the
function-level attribute.

But this raises a bug noted by the new FIXME comment.

In order to do this transform:
sqrt((x * x) * y) ---> fabs(x) * sqrt(y)

...we need all of the sqrt, the first fmul, and the second fmul to be 'fast'. 
If any of those ops is strict, we should bail out.

Differential Revision: http://reviews.llvm.org/D15937

llvm-svn: 257400
2016-01-11 22:34:19 +00:00
Sanjay Patel
c2d6461a4a [LibCallSimplifier] less indenting; NFCI
llvm-svn: 256973
2016-01-06 20:52:21 +00:00
Sanjay Patel
cddcd7256c [LibCallSimplifier] use instruction-level fast-math-flags for tan/atan transform
llvm-svn: 256964
2016-01-06 19:23:35 +00:00
David Majnemer
b70e23c390 [SimplifyLibCalls] Teach SimplifyLibCalls about operand bundles
If we replace one call-site with another, be sure to move over any
operand bundles that lingered on the old call-site.

This fixes PR26036.

llvm-svn: 256912
2016-01-06 05:01:34 +00:00
Sanjay Patel
c7ddb7fcdb A (B + C) = A B + A C ; NFCI
llvm-svn: 256884
2016-01-06 00:32:15 +00:00
Sanjay Patel
29095ea1b0 [LibCallSimplfier] use instruction-level fast-math-flags for fmin/fmax transforms
llvm-svn: 256871
2016-01-05 20:46:19 +00:00
Sanjay Patel
bee05caa6b [LibCallSimplifier] propagate FMF when shrinking binary calls
llvm-svn: 256682
2015-12-31 23:40:59 +00:00
Sanjay Patel
aa23114cb4 [LibCallSimplifier] propagate FMF when shrinking unary calls
llvm-svn: 256679
2015-12-31 21:52:31 +00:00
Sanjay Patel
96475cbd22 Variable names start with an upper case letter; NFC
llvm-svn: 256676
2015-12-31 16:16:58 +00:00
Sanjay Patel
d707db97a9 fix formatting; NFC
llvm-svn: 256675
2015-12-31 16:10:49 +00:00
Sanjay Patel
af674fbfd9 getParent() ^ 3 == getModule() ; NFCI
llvm-svn: 255511
2015-12-14 17:24:23 +00:00
Weiming Zhao
8213072a45 [SimplifyLibCalls] Optimization for pow(x, n) where n is some constant
Summary:
    In order to avoid calling pow function we generate repeated fmul when n is a
    positive or negative whole number.
    
    For each exponent we pre-compute Addition Chains in order to minimize the no.
    of fmuls.
    Refer: http://wwwhomes.uni-bielefeld.de/achim/addition_chain.html
    
    We pre-compute addition chains for exponents upto 32 (which results in a max of
    7 fmuls).

    For eg:
    4 = 2+2
    5 = 2+3
    6 = 3+3 and so on
    
    Hence,
    pow(x, 4.0) ==> y = fmul x, x
                    x = fmul y, y
                    ret x

    For negative exponents, we simply compute the reciprocal of the final result.
    
    Note: This transformation is only enabled under fast-math.
    
    Patch by Mandeep Singh Grang <mgrang@codeaurora.org>

Reviewers: weimingz, majnemer, escha, davide, scanon, joerg

Subscribers: probinson, escha, llvm-commits

Differential Revision: http://reviews.llvm.org/D13994

llvm-svn: 254776
2015-12-04 22:00:47 +00:00
Davide Italiano
1aeed6a955 [SimplifyLibCalls] Transform log(exp2(y)) to y*log(2) under fast-math.
llvm-svn: 254317
2015-11-30 19:36:35 +00:00
Davide Italiano
0b14f29285 [SimplifyLibCalls] Don't crash if the function doesn't have a name.
llvm-svn: 254265
2015-11-29 21:58:56 +00:00
Davide Italiano
e2db58cfb8 [SimplifyLibCalls] Cross out implemented transformations.
llvm-svn: 254264
2015-11-29 21:00:43 +00:00
Davide Italiano
b8b7133c94 [SimplifyLibCalls] Tranform log(pow(x, y)) -> y*log(x).
This one is enabled only under -ffast-math. There are cases where the
difference between the value computed and the correct value is huge
even for ffast-math, e.g. as Steven pointed out:

x = -1, y = -4
log(pow(-1), 4) = 0
4*log(-1) = NaN

I checked what GCC does and apparently they do the same optimization
(which result in the dramatic difference). Future work might try to
make this (slightly) less worse.

Differential Revision:	http://reviews.llvm.org/D14400

llvm-svn: 254263
2015-11-29 20:58:04 +00:00
Davide Italiano
da3beebad1 [SimplifyLibCalls] Use any_of(). Suggested by David Blaikie!
llvm-svn: 254239
2015-11-28 22:27:48 +00:00