Commit Graph

45 Commits

Author SHA1 Message Date
David Blaikie f72d05bc7b [opaque pointer type] Add textual IR support for explicit type parameter to gep operator
Similar to gep (r230786) and load (r230794) changes.

Similar migration script can be used to update test cases, which
successfully migrated all of LLVM and Polly, but about 4 test cases
needed manually changes in Clang.

(this script will read the contents of stdin and massage it into stdout
- wrap it in the 'apply.sh' script shown in previous commits + xargs to
apply it over a large set of test cases)

import fileinput
import sys
import re

rep = re.compile(r"(getelementptr(?:\s+inbounds)?\s*\()((<\d*\s+x\s+)?([^@]*?)(|\s*addrspace\(\d+\))\s*\*(?(3)>)\s*)(?=$|%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|zeroinitializer|<|\[\[[a-zA-Z]|\{\{)", re.MULTILINE | re.DOTALL)

def conv(match):
  line = match.group(1)
  line += match.group(4)
  line += ", "
  line += match.group(2)
  return line

line = sys.stdin.read()
off = 0
for match in re.finditer(rep, line):
  sys.stdout.write(line[off:match.start()])
  sys.stdout.write(conv(match))
  off = match.end()
sys.stdout.write(line[off:])

llvm-svn: 232184
2015-03-13 18:20:45 +00:00
David Blaikie a79ac14fa6 [opaque pointer type] Add textual IR support for explicit type parameter to load instruction
Essentially the same as the GEP change in r230786.

A similar migration script can be used to update test cases, though a few more
test case improvements/changes were required this time around: (r229269-r229278)

import fileinput
import sys
import re

pat = re.compile(r"((?:=|:|^)\s*load (?:atomic )?(?:volatile )?(.*?))(| addrspace\(\d+\) *)\*($| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$)")

for line in sys.stdin:
  sys.stdout.write(re.sub(pat, r"\1, \2\3*\4", line))

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7649

llvm-svn: 230794
2015-02-27 21:17:42 +00:00
David Blaikie 79e6c74981 [opaque pointer type] Add textual IR support for explicit type parameter to getelementptr instruction
One of several parallel first steps to remove the target type of pointers,
replacing them with a single opaque pointer type.

This adds an explicit type parameter to the gep instruction so that when the
first parameter becomes an opaque pointer type, the type to gep through is
still available to the instructions.

* This doesn't modify gep operators, only instructions (operators will be
  handled separately)

* Textual IR changes only. Bitcode (including upgrade) and changing the
  in-memory representation will be in separate changes.

* geps of vectors are transformed as:
    getelementptr <4 x float*> %x, ...
  ->getelementptr float, <4 x float*> %x, ...
  Then, once the opaque pointer type is introduced, this will ultimately look
  like:
    getelementptr float, <4 x ptr> %x
  with the unambiguous interpretation that it is a vector of pointers to float.

* address spaces remain on the pointer, not the type:
    getelementptr float addrspace(1)* %x
  ->getelementptr float, float addrspace(1)* %x
  Then, eventually:
    getelementptr float, ptr addrspace(1) %x

Importantly, the massive amount of test case churn has been automated by
same crappy python code. I had to manually update a few test cases that
wouldn't fit the script's model (r228970,r229196,r229197,r229198). The
python script just massages stdin and writes the result to stdout, I
then wrapped that in a shell script to handle replacing files, then
using the usual find+xargs to migrate all the files.

update.py:
import fileinput
import sys
import re

ibrep = re.compile(r"(^.*?[^%\w]getelementptr inbounds )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")
normrep = re.compile(       r"(^.*?[^%\w]getelementptr )(((?:<\d* x )?)(.*?)(| addrspace\(\d\)) *\*(|>)(?:$| *(?:%|@|null|undef|blockaddress|getelementptr|addrspacecast|bitcast|inttoptr|\[\[[a-zA-Z]|\{\{).*$))")

def conv(match, line):
  if not match:
    return line
  line = match.groups()[0]
  if len(match.groups()[5]) == 0:
    line += match.groups()[2]
  line += match.groups()[3]
  line += ", "
  line += match.groups()[1]
  line += "\n"
  return line

for line in sys.stdin:
  if line.find("getelementptr ") == line.find("getelementptr inbounds"):
    if line.find("getelementptr inbounds") != line.find("getelementptr inbounds ("):
      line = conv(re.match(ibrep, line), line)
  elif line.find("getelementptr ") != line.find("getelementptr ("):
    line = conv(re.match(normrep, line), line)
  sys.stdout.write(line)

apply.sh:
for name in "$@"
do
  python3 `dirname "$0"`/update.py < "$name" > "$name.tmp" && mv "$name.tmp" "$name"
  rm -f "$name.tmp"
done

The actual commands:
From llvm/src:
find test/ -name *.ll | xargs ./apply.sh
From llvm/src/tools/clang:
find test/ -name *.mm -o -name *.m -o -name *.cpp -o -name *.c | xargs -I '{}' ../../apply.sh "{}"
From llvm/src/tools/polly:
find test/ -name *.ll | xargs ./apply.sh

After that, check-all (with llvm, clang, clang-tools-extra, lld,
compiler-rt, and polly all checked out).

The extra 'rm' in the apply.sh script is due to a few files in clang's test
suite using interesting unicode stuff that my python script was throwing
exceptions on. None of those files needed to be migrated, so it seemed
sufficient to ignore those cases.

Reviewers: rafael, dexonsmith, grosser

Differential Revision: http://reviews.llvm.org/D7636

llvm-svn: 230786
2015-02-27 19:29:02 +00:00
Matt Arsenault fd78d0c934 Look through addrspacecast in GetPointerBaseWithConstantOffset
llvm-svn: 212999
2014-07-14 22:39:22 +00:00
Shuxin Yang 3168ab3376 Fix PR17952.
The symptom is that an assertion is triggered. The assertion was added by
me to detect the situation when value is propagated from dead blocks.
(We can certainly get rid of assertion; it is safe to do so, because propagating
 value from dead block to alive join node is certainly ok.)

  The root cause of this bug is : edge-splitting is conducted on the fly,
the edge being split could be a dead edge, therefore the block that 
split the critial edge needs to be flagged "dead" as well.

  There are 3 ways to fix this bug:
  1) Get rid of the assertion as I mentioned eariler 
  2) When an dead edge is split, flag the inserted block "dead".
  3) proactively split the critical edges connecting dead and live blocks when
     new dead blocks are revealed.

  This fix go for 3) with additional 2 LOC.

  Testing case was added by Rafael the other day.

llvm-svn: 194424
2013-11-11 22:00:23 +00:00
Bill Wendling fed6c220ec Revert "Resurrect r191017 " GVN proceeds in the presence of dead code" plus a fix to PR17307 & 17308."
This causes PR17852.

This reverts commit d93e8a06b2ca09ab18f390cd514b7443e2e571f7.

Conflicts:
	test/Transforms/GVN/cond_br2.ll

llvm-svn: 194348
2013-11-10 07:34:34 +00:00
Matt Arsenault 614ea99da7 Fix GVN creating bitcast between address spaces
llvm-svn: 193710
2013-10-30 19:05:41 +00:00
Shuxin Yang 6e35094bbf Resurrect r191017 " GVN proceeds in the presence of dead code" plus a fix to PR17307 & 17308.
The problem of r191017 is that when GVN fabricate a val-number for a dead instruction (in order
to make following expr-PRE happy), it forget to fabricate a leader-table entry for it as well.

llvm-svn: 191118
2013-09-20 23:12:57 +00:00
Joerg Sonnenberger 1fbe323649 Revert r191017, it results in segmentation faults in Qt.
llvm-svn: 191104
2013-09-20 20:33:57 +00:00
Shuxin Yang 74c9a170b8 GVN proceeds in the presence of dead code.
This is how it ignores the dead code:
1) When a dead branch target, say block B, is identified, all the
    blocks dominated by B is dead as well.

2) The PHIs of those blocks in dominance-frontier(B) is updated such
   that the operands corresponding to dead predecessors are replaced
   by "UndefVal".

   Using lattice's jargon, the "UndefVal" is the "Top" in essence.
   Phi node like this "phi(v1 bb1, undef xx)" will be optimized into
   "v1" if v1 is constant, or v1 is an instruction which dominate this
   PHI node.

3) When analyzing the availability of a load L, all dead mem-ops which
   L depends on disguise as a load which evaluate exactly same value as L.

4) The dead mem-ops will be materialized as "UndefVal" during code motion.

llvm-svn: 191017
2013-09-19 17:22:51 +00:00
Stephen Lin c1c7a1309c Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.
This update was done with the following bash script:

  find test/Transforms -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc" $NAME; then
      TEMP=`mktemp -t temp`
      cp $NAME $TEMP
      sed -n "s/^define [^@]*@\([A-Za-z0-9_]*\)(.*$/\1/p" < $NAME | \
      while read FUNC; do
        sed -i '' "s/;\(.*\)\([A-Za-z0-9_]*\):\( *\)@$FUNC\([( ]*\)\$/;\1\2-LABEL:\3@$FUNC(/g" $TEMP
      done
      mv $TEMP $NAME
    fi
  done

llvm-svn: 186268
2013-07-14 01:42:54 +00:00
Jakub Staszak 0a74fc8d6c unHECKify test. It was fixed by Chris in 2009.
llvm-svn: 170017
2012-12-12 20:43:00 +00:00
NAKAMURA Takumi 43ab4ef9ba llvm/ConstantFolding.cpp: Make ReadDataFromGlobal() and FoldReinterpretLoadFromConstPtr() Big-endian-aware.
llvm-svn: 167595
2012-11-08 20:34:25 +00:00
Benjamin Kramer 2f47a3fb07 Fix broken check lines.
I really need to find a way to automate this, but I can't come up with a regex
that has no false positives while handling tricky cases like custom check
prefixes.

llvm-svn: 162097
2012-08-17 12:28:26 +00:00
Nick Lewycky 063ae5897c Fix crasher in GVN due to my recent capture tracking changes.
llvm-svn: 145047
2011-11-21 19:42:56 +00:00
Nick Lewycky 7013a19e8a Refactor capture tracking (which already had a couple flags for whether returns
and stores capture) to permit the caller to see each capture point and decide
whether to continue looking.

Use this inside memdep to do an analysis that basicaa won't do. This lets us
solve another devirtualization case, fixing PR8908!

llvm-svn: 144580
2011-11-14 22:49:42 +00:00
Chris Lattner 80ed9dc9e5 rip out a ton of intrinsic modernization logic from AutoUpgrade.cpp, which is
for pre-2.9 bitcode files.  We keep x86 unaligned loads, movnt, crc32, and the
target indep prefetch change.

As usual, updating the testsuite is a PITA.

llvm-svn: 133337
2011-06-18 06:05:24 +00:00
Dan Gohman a471751c24 Disable the main feature of 130180, the elimination of loads that are
redundant with partially-aliasing loads.

When computing what portion of a clobbering load value is needed,
it doesn't consider phi-translation which may have occurred
between the clobbing load and the redundant load.

llvm-svn: 132631
2011-06-04 06:48:50 +00:00
Chris Lattner a10327f531 remove a trivial test, make some other tests less trivial.
llvm-svn: 131846
2011-05-22 07:02:43 +00:00
Chris Lattner 1777601a74 final step needed to resolve PR6627, which allows us to flatten the code down to
a nice and tidy:
  %x1 = load i32* %0, align 4
  %1 = icmp eq i32 %x1, 1179403647
  br i1 %1, label %if.then, label %if.end

instead of doing lots of loads and branches.  May the FreeBSD bootloader
long fit in its allocated space.

llvm-svn: 130416
2011-04-28 18:15:47 +00:00
Chris Lattner 827a270a2a teach GVN to widen integer loads when they are overaligned, when doing an
wider load would allow elimination of subsequent loads, and when the wider
load is still a native integer type.  This eliminates a ton of loads on 
various benchmarks involving struct fields, though it is somewhat hobbled
by clang not being very aggressive about field alignment.

This is yet another step along the way towards resolving PR6627.

llvm-svn: 130390
2011-04-28 07:29:08 +00:00
Chris Lattner eb045f9c02 Improve the bail-out predicate to really only kick in when phi
translation fails.  We were bailing out in some cases that would
cause us to miss GVN'ing some non-local cases away.

llvm-svn: 130206
2011-04-26 17:41:02 +00:00
Chris Lattner 6f83d06ffa Enhance MemDep: When alias analysis returns a partial alias result,
return it as a clobber.  This allows GVN to do smart things.

Enhance GVN to be smart about the case when a small load is clobbered
by a larger overlapping load.  In this case, forward the value.  This
allows us to compile stuff like this:

int test(void *P) {
  int tmp = *(unsigned int*)P;
  return tmp+*((unsigned char*)P+1);
}

into:

_test:                                  ## @test
	movl	(%rdi), %ecx
	movzbl	%ch, %eax
	addl	%ecx, %eax
	ret

which has one load.  We already handled the case where the smaller
load was from a must-aliased base pointer.

llvm-svn: 130180
2011-04-26 01:21:15 +00:00
Dan Gohman 02538ac4d3 Make BasicAliasAnalysis a normal AliasAnalysis implementation which
does normal initialization and normal chaining. Change the default
AliasAnalysis implementation to NoAlias.

Update StandardCompileOpts.h and friends to explicitly request
BasicAliasAnalysis.

Update tests to explicitly request -basicaa.

llvm-svn: 116720
2010-10-18 18:04:47 +00:00
Chris Lattner 0563804982 fix PR6642, GVN forwarding from memset to load of the base of the memset.
llvm-svn: 99488
2010-03-25 05:58:19 +00:00
Chris Lattner ca5f9cb18b fix hte last remaining known (by me) phi translation bug. When we reanalyze
clobbers to forward pieces of large stores to small loads, we need to consider
the properly phi translated pointer in the store block.

llvm-svn: 90978
2009-12-09 18:21:46 +00:00
Chris Lattner 10398e74ae the code in GVN that tries to forward large loads to small
stores is not phi translating, thus it miscompiles really
crazy testcases.  This is from inspection, I haven't seen
this in the wild.

llvm-svn: 90930
2009-12-09 02:43:05 +00:00
Chris Lattner 972e6d8d00 Switch GVN and memdep to use PHITransAddr, which correctly handles
phi translation of complex expressions like &A[i+1].  This has the
following benefits:

1. The phi translation logic is all contained in its own class with
   a strong interface and verification that it is self consistent.

2. The logic is more correct than before.  Previously, if intermediate
   expressions got PHI translated, we'd miss the update and scan for
   the wrong pointers in predecessor blocks.  @phi_trans2 is a testcase
   for this.

3. We have a lot less code in memdep.

We can handle phi translation across blocks of things like @phi_trans3,
which is pretty insane :).

This patch should fix the miscompiles of 255.vortex, and I tested it 
with a bootstrap of llvm-gcc, llvm-test and dejagnu of course.

llvm-svn: 90926
2009-12-09 01:59:31 +00:00
Chris Lattner 778cb92235 constant fold loads from memcpy's from global constants. This is important
because clang lowers nontrivial automatic struct/array inits to memcpy from
a global array.

llvm-svn: 90698
2009-12-06 05:29:56 +00:00
Chris Lattner 93236ba327 add support for forwarding mem intrinsic values to non-local loads.
llvm-svn: 90697
2009-12-06 04:54:31 +00:00
Chris Lattner 42376066eb Handle forwarding local memsets to loads. For example, we optimize this:
short x(short *A) {
  memset(A, 1, sizeof(*A)*100);
  return A[42];
}

to 'return 257' instead of doing the load.  

llvm-svn: 90695
2009-12-06 01:57:02 +00:00
Chris Lattner eb5bb1bf78 merge two tests.
llvm-svn: 90691
2009-12-06 01:47:24 +00:00
Chris Lattner 1c21aaca06 Small and carefully crafted testcase showing a miscompilation by GVN
that I'm working on.  This is manifesting as a miscompile of 255.vortex
on some targets.  No check lines yet because it fails.

llvm-svn: 90520
2009-12-04 02:12:12 +00:00
Chris Lattner 9045f235d2 fix PR5016, a crash I introduced in GVN handing first class
arrays and structs, which cannot be bitcast to integers.

llvm-svn: 82460
2009-09-21 17:24:04 +00:00
Chris Lattner 4d8af2f1ae enable non-local analysis and PRE of large store -> little load.
This doesn't kick in too much because of phi translation issues,
but this can be resolved in the future.

llvm-svn: 82447
2009-09-21 06:48:08 +00:00
Chris Lattner e2b8a80487 add pr#
llvm-svn: 82440
2009-09-21 05:57:47 +00:00
Chris Lattner 0a9616d906 Improve GVN to be able to forward substitute a small load
from a piece of a large store when both are in the same block.

This allows clang to compile the testcase in PR4216 to this code:

_test_bitfield:
	movl	4(%esp), %eax
	movl	%eax, %ecx
	andl	$-65536, %ecx
	orl	$32962, %eax
	andl	$40186, %eax
	orl	%ecx, %eax
	ret

This is not ideal, but is a whole lot better than the code produced
by llvm-gcc:

_test_bitfield:
	movw	$-32574, %ax
	orw	4(%esp), %ax
	andw	$-25350, %ax
	movw	%ax, 4(%esp)
	movw	7(%esp), %cx
	shlw	$8, %cx
	movzbl	6(%esp), %edx
	orw	%cx, %dx
	movzwl	%dx, %ecx
	shll	$16, %ecx
	movzwl	%ax, %eax
	orl	%ecx, %eax
	ret

and dramatically better than that produced by gcc 4.2:

_test_bitfield:
	pushl	%ebx
	call	L3
"L00000000001$pb":
L3:
	popl	%ebx
	movl	8(%esp), %eax
	leal	0(,%eax,4), %edx
	sarb	$7, %dl
	movl	%eax, %ecx
	andl	$7168, %ecx
	andl	$-7201, %ebx
	movzbl	%dl, %edx
	andl	$1, %edx
	sall	$5, %edx
	orl	%ecx, %ebx
	orl	%edx, %ebx
	andl	$24, %eax
	andl	$-58336, %ebx
	orl	%eax, %ebx
	orl	$32962, %ebx
	movl	%ebx, %eax
	popl	%ebx
	ret

llvm-svn: 82439
2009-09-21 05:57:11 +00:00
Chris Lattner b9f2bf46f7 fix a FileCheck bug where:
; CHECK: foo
; CHECK-NOT: foo
; CHECK: bar

would always fail.

llvm-svn: 82424
2009-09-21 02:30:42 +00:00
Daniel Dunbar ffb60d566f Work around a FileCheck bug, for now.
llvm-svn: 82416
2009-09-20 23:30:31 +00:00
Chris Lattner 7e6d56ebc5 Revert r82404, it is causing a bootstrap miscompile. This is very very
scary, as it indicates a lurking bug. yay.

llvm-svn: 82411
2009-09-20 22:44:26 +00:00
Chris Lattner 973f14c8fa this was not supposed to be committed
llvm-svn: 82409
2009-09-20 22:36:11 +00:00
Chris Lattner 236d2d5e7b implement and document support for CHECK-NOT
llvm-svn: 82408
2009-09-20 22:35:26 +00:00
Chris Lattner eea16a168a improve memdep to eliminate bitcasts (and aliases, and noop geps)
early for the stated reasons: this allows it to find more 
equivalences and depend less on code layout.

llvm-svn: 82404
2009-09-20 21:00:18 +00:00
Chris Lattner a0aa8fb6a6 Move CoerceAvailableValueToLoadType earlier in GVN.cpp. Hook it up
so that nonlocal and partially redundant loads can use it as well.
The testcase shows examples of craziness this can handle.  This triggers
*many* times in 176.gcc.

llvm-svn: 82403
2009-09-20 20:09:34 +00:00
Chris Lattner 1dd48c34e5 enhance GVN to forward substitute a stored value to a load
(and load -> load) when the base pointers must alias but when
they are different types.  This occurs very very frequently in
176.gcc and other code that uses bitfields a lot.

llvm-svn: 82399
2009-09-20 19:03:47 +00:00