16 Commits

Author SHA1 Message Date
Hans Wennborg 1c74502fd9 Re-commit r265039 "[X86] Merge adjacent stack adjustments in eliminateCallFramePseudoInstr (PR27140)"
Third time's the charm? The previous attempt (r265345) caused ASan test
failures on X86, as broken CFI caused stack traces to not work.

This version of the patch makes sure not to merge with stack adjustments
that have CFI, and to not add merged instructions' offests to the CFI
about to be generated.

This is already covered by the lit tests; I just got the expectations
wrong previously.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265623 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-07 00:05:49 +00:00
Hans Wennborg 374df657de Revert "Re-commit r265039 "[X86] Merge adjacent stack adjustments in eliminateCallFramePseudoInstr (PR27140)""
It seems to be causing ASan tests to crash, probably due to
miscompiling the run-time somehow.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265551 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-06 16:10:20 +00:00
Hans Wennborg 5ef7ab8d71 Re-commit r265039 "[X86] Merge adjacent stack adjustments in eliminateCallFramePseudoInstr (PR27140)"
The original commit miscompiled things on 32-bit Windows, e.g. a Clang
boostrap. It turns out that mergeSPUpdates() was a bit too generous in
what it interpreted as a stack adjustment, causing the following code:

        addl    $12, %esp
        leal    -4(%ebp), %esp

To be "optimized" into simply:

        addl    $8, %esp

This commit tightens up mergeSPUpdates() and includes a new test
(test14 in movtopush.ll) for this situation.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265345 91177308-0d34-0410-b5e6-96231b3b80d8
2016-04-04 21:02:46 +00:00
Hans Wennborg b7cecbaebd Revert r265039 "[X86] Merge adjacent stack adjustments in eliminateCallFramePseudoInstr (PR27140)"
I think it might have caused these build breakages:
http://lab.llvm.org:8011/builders/clang-x86-win2008-selfhost/builds/7234/steps/build%20stage%202/logs/stdio
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/19566/steps/run%20tests/logs/stdio

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265046 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 20:27:30 +00:00
Hans Wennborg 4d88edd42f [X86] Merge adjacent stack adjustments in eliminateCallFramePseudoInstr (PR27140)
For code such as:

  void f(int, int);
  void g() {
      f(1, 2);
  }

compiled for 32-bit X86 Linux, Clang would previously generate:

  subl    $12, %esp
  subl    $8, %esp
  pushl   $2
  pushl   $1
  calll   f
  addl    $16, %esp
  addl    $12, %esp
  retl

This patch fixes that by merging adjacent stack adjustments in
eliminateCallFramePseudoInstr().

Differential Revision: http://reviews.llvm.org/D18627

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@265039 91177308-0d34-0410-b5e6-96231b3b80d8
2016-03-31 19:26:24 +00:00
Pete Cooper 6d024c616a Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253543 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-19 05:56:52 +00:00
Pete Cooper 8b170f7f29 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@253511 91177308-0d34-0410-b5e6-96231b3b80d8
2015-11-18 22:17:24 +00:00
Akira Hatanaka 8e2b613ef0 Use function attribute "stackrealign" to decide whether stack
realignment should be forced.

With this commit, we can now force stack realignment when doing LTO and
do so on a per-function basis. Also, add a new cl::opt option
"stackrealign" to CommandFlags.h which is used to force stack
realignment via llc's command line.

Out-of-tree projects currently using -force-align-stack to force stack
realignment should make changes to attach the attribute to the functions
in the IR.

Differential Revision: http://reviews.llvm.org/D11814


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247450 91177308-0d34-0410-b5e6-96231b3b80d8
2015-09-11 18:54:38 +00:00
David Blaikie 7c9c6ed761 [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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@230794 91177308-0d34-0410-b5e6-96231b3b80d8
2015-02-27 21:17:42 +00:00
Michael Kuperstein 77c1b73211 [X86] Convert esp-relative movs of function arguments into pushes, step 1
This handles the simplest case for mov -> push conversion:
1. x86-32 calling convention, everything is passed through the stack.
2. There is no reserved call frame.
3. Only registers or immediates are pushed, no attempt to combine a mem-reg-mem sequence into a single PUSHmm.

Differential Revision: http://reviews.llvm.org/D6503

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@223757 91177308-0d34-0410-b5e6-96231b3b80d8
2014-12-09 06:10:44 +00:00
Stephen Lin 8b2b8a1835 Mass update to CodeGen tests to use CHECK-LABEL for labels corresponding to function definitions for more informative error messages. No functionality change and all updated tests passed locally.
This update was done with the following bash script:

  find test/CodeGen -name "*.ll" | \
  while read NAME; do
    echo "$NAME"
    if ! grep -q "^; *RUN: *llc.*debug" $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
      sed -i '' "s/;\(.*\)-LABEL-LABEL:/;\1-LABEL:/" $TEMP
      sed -i '' "s/;\(.*\)-NEXT-LABEL:/;\1-NEXT:/" $TEMP
      sed -i '' "s/;\(.*\)-NOT-LABEL:/;\1-NOT:/" $TEMP
      sed -i '' "s/;\(.*\)-DAG-LABEL:/;\1-DAG:/" $TEMP
      mv $TEMP $NAME
    fi
  done


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@186280 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-14 06:24:09 +00:00
Chad Rosier d97f3a5ab0 [x86 frame lowering] In 32-bit mode, use ESI as the base pointer.
Previously, we were using EBX, but PIC requires the GOT to be in EBX before 
function calls via PLT GOT pointer.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@161066 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-31 18:29:21 +00:00
Preston Gurd 5b50701b1c Fix remaining lit tests which were failing when run on an Atom
processor.

Patches by Tyler Nowicki, Andy Zhang, and Preston Gurd!



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160520 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-19 18:53:21 +00:00
Alexey Samsonov 99a92f269d This CL changes the function prologue and epilogue emitted on X86 when stack needs realignment.
It is intended to fix PR11468.

Old prologue and epilogue looked like this:
push %rbp
mov %rsp, %rbp
and $alignment, %rsp
push %r14
push %r15
...
pop %r15
pop %r14
mov %rbp, %rsp
pop %rbp

The problem was to reference the locations of callee-saved registers in exception handling:
locations of callee-saved had to be re-calculated regarding the stack alignment operation. It would
take some effort to implement this in LLVM, as currently MachineLocation can only have the form
"Register + Offset". Funciton prologue and epilogue are now changed to:

push %rbp
mov %rsp, %rbp
push %14
push %15
and $alignment, %rsp
...
lea -$size_of_saved_registers(%rbp), %rsp
pop %r15
pop %r14
pop %rbp

Reviewed by Chad Rosier.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160248 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-16 06:54:09 +00:00
Chad Rosier 3f0dbab963 Add support for dynamic stack realignment in the presence of dynamic allocas on
X86.  Basically, this is a reapplication of r158087 with a few fixes.

Specifically, (1) the stack pointer is restored from the base pointer before
popping callee-saved registers and (2) in obscure cases (see comments in patch)
we must cache the value of the original stack adjustment in the prologue and
apply it in the epilogue.

rdar://11496434


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160002 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-10 17:45:53 +00:00
Chandler Carruth 457dfbac8a Add a regression test for the bug exposed by r158087, which has been
temporarily reverted.

This test is annoyingly overspecified, but I don't know of another way
to thoroughly test the saving and restoring of the registers. While this
will have to be adjusted even with the issue fixed in order to re-apply
r158087, those adjustments should very clearly indicate that it is still
correct (%esp getting restored prior to pops), whereas without it, this
case can easily slip under the radar.

Still, any suggestions for improvements are very welcome.

All credit to Matt Beaumont-Gay for reducing this out of an insane
Address Sanitizer crash to a reasonably small seg-faulting C program
when built with -mstackrealign. I just reduced it to IR, which was much
simpler. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158656 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-18 09:15:04 +00:00