Commit Graph

8 Commits

Author SHA1 Message Date
Hans Wennborg ab16be799c 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.

llvm-svn: 265623
2016-04-07 00:05:49 +00:00
Hans Wennborg a7e396b5ef 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.

llvm-svn: 265551
2016-04-06 16:10:20 +00:00
Hans Wennborg a47a692341 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.

llvm-svn: 265345
2016-04-04 21:02:46 +00:00
Adrian Prantl b8089516a5 testcase gardening: update the emissionKind enum to the new syntax. (NFC)
llvm-svn: 265081
2016-04-01 00:16:49 +00:00
Hans Wennborg 132cd62121 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

llvm-svn: 265046
2016-03-31 20:27:30 +00:00
Hans Wennborg e97fb414e8 [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

llvm-svn: 265039
2016-03-31 19:26:24 +00:00
Peter Collingbourne d4bff30370 DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

llvm-svn: 252219
2015-11-05 22:03:56 +00:00
Michael Kuperstein 73dc85293f [X86] Generate .cfi_adjust_cfa_offset correctly when pushing arguments
When push instructions are being used to pass function arguments on
the stack, and either EH or debugging are enabled, we need to generate
.cfi_adjust_cfa_offset directives appropriately. For (synch) EH, it is
enough for the CFA offset to be correct at every call site, while
for debugging we want to be correct after every push.

Darwin does not support this well, so don't use pushes whenever it
would be required.

Differential Revision: http://reviews.llvm.org/D13767

llvm-svn: 251904
2015-11-03 08:17:25 +00:00