Commit Graph

7 Commits

Author SHA1 Message Date
Matthias Braun 6b898beb8e X86: Do not use llc -march in tests.
`llc -march` is problematic because it only switches the target
architecture, but leaves the operating system unchanged. This
occasionally leads to indeterministic tests because the OS from
LLVM_DEFAULT_TARGET_TRIPLE is used.

However we can simply always use `llc -mtriple` instead. This changes
all the tests to do this to avoid people using -march when they copy and
paste parts of tests.

See also the discussion in https://reviews.llvm.org/D35287

llvm-svn: 309774
2017-08-02 00:28:10 +00:00
Kevin B. Smith 54566a0e9a [X86]: Quit promoting 8 and 16 bit compares to 32 bit.
Differential Revision: http://reviews.llvm.org/D21144

llvm-svn: 272801
2016-06-15 16:37:46 +00:00
Tim Northover 277066ab43 X86: expand atomics in IR instead of as MachineInstrs.
The logic for expanding atomics that aren't natively supported in
terms of cmpxchg loops is much simpler to express at the IR level. It
also allows the normal optimisations and CodeGen improvements to help
out with atomics, instead of using a limited set of possible
instructions..

rdar://problem/13496295

llvm-svn: 212119
2014-07-01 18:53:31 +00:00
Tim Northover e94a518a22 IR: add a second ordering operand to cmpxhg for failure
The syntax for "cmpxchg" should now look something like:

	cmpxchg i32* %addr, i32 42, i32 3 acquire monotonic

where the second ordering argument gives the required semantics in the case
that no exchange takes place. It should be no stronger than the first ordering
constraint and cannot be either "release" or "acq_rel" (since no store will
have taken place).

rdar://problem/15996804

llvm-svn: 203559
2014-03-11 10:48:52 +00:00
Michael Liao da22b30be5 Fix PR15355
- Clear 'mayStore' flag when loading from the atomic variable before the
  spin loop
- Clear kill flag from one use to multiple use in registers forming the
  address to that atomic variable
- don't use a physical register as live-in register in BB (neither entry
  nor landing pad.) by copying it into virtual register

(patch by Cameron Zwarich)

llvm-svn: 176538
2013-03-06 00:17:04 +00:00
Michael Liao a880186030 Add missing i8 max/min/umax/umin support
- Fix PR5145 and turn on test 8-bit atomic ops

llvm-svn: 164358
2012-09-21 03:18:52 +00:00
Michael Liao 3237662b65 Re-work X86 code generation of atomic ops with spin-loop
- Rewrite/merge pseudo-atomic instruction emitters to address the
  following issue:
  * Reduce one unnecessary load in spin-loop

    previously the spin-loop looks like

        thisMBB:
        newMBB:
          ld  t1 = [bitinstr.addr]
          op  t2 = t1, [bitinstr.val]
          not t3 = t2  (if Invert)
          mov EAX = t1
          lcs dest = [bitinstr.addr], t3  [EAX is implicit]
          bz  newMBB
          fallthrough -->nextMBB

    the 'ld' at the beginning of newMBB should be lift out of the loop
    as lcs (or CMPXCHG on x86) will load the current memory value into
    EAX. This loop is refined as:

        thisMBB:
          EAX = LOAD [MI.addr]
        mainMBB:
          t1 = OP [MI.val], EAX
          LCMPXCHG [MI.addr], t1, [EAX is implicitly used & defined]
          JNE mainMBB
        sinkMBB:

  * Remove immopc as, so far, all pseudo-atomic instructions has
    all-register form only, there is no immedidate operand.

  * Remove unnecessary attributes/modifiers in pseudo-atomic instruction
    td

  * Fix issues in PR13458

- Add comprehensive tests on atomic ops on various data types.
  NOTE: Some of them are turned off due to missing functionality.

- Revise tests due to the new spin-loop generated.

llvm-svn: 164281
2012-09-20 03:06:15 +00:00