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| author | Robin Morisset <morisset@google.com> | 2014-10-03 18:04:36 +0000 |
|---|---|---|
| committer | Robin Morisset <morisset@google.com> | 2014-10-03 18:04:36 +0000 |
| commit | 9098fee6905d407723a7e624e31087554fab662c (patch) | |
| tree | d464d8058b8e833f1987d535f078fa7ec14740bb | |
| parent | 92e31a5ead9b0d29418d02b610d8bb8fa428000e (diff) | |
| download | bcm5719-llvm-9098fee6905d407723a7e624e31087554fab662c.tar.gz bcm5719-llvm-9098fee6905d407723a7e624e31087554fab662c.zip | |
[Power] Use lwsync for non-seq_cst fences
Summary:
hwsync is only required for seq_cst fences, acquire and release one can use
the cheaper lwsync.
Test Plan: Added some cases to atomics.ll + make check-all
Reviewers: jfb, wschmidt
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D5317
llvm-svn: 218995
| -rw-r--r-- | llvm/lib/Target/PowerPC/PPCInstrInfo.td | 9 | ||||
| -rw-r--r-- | llvm/test/CodeGen/PowerPC/atomics-fences.ll | 29 |
2 files changed, 37 insertions, 1 deletions
diff --git a/llvm/lib/Target/PowerPC/PPCInstrInfo.td b/llvm/lib/Target/PowerPC/PPCInstrInfo.td index fe85e8209f7..a480757a600 100644 --- a/llvm/lib/Target/PowerPC/PPCInstrInfo.td +++ b/llvm/lib/Target/PowerPC/PPCInstrInfo.td @@ -2549,7 +2549,14 @@ def : Pat<(f64 (extloadf32 xaddr:$src)), def : Pat<(f64 (fextend f32:$src)), (COPY_TO_REGCLASS $src, F8RC)>; -def : Pat<(atomic_fence (imm), (imm)), (SYNC 0)>, Requires<[HasSYNC]>; +// Only seq_cst fences require the heavyweight sync (SYNC 0). +// All others can use the lightweight sync (SYNC 1). +// source: http://www.cl.cam.ac.uk/~pes20/cpp/cpp0xmappings.html +// The rule for seq_cst is duplicated to work with both 64 bits and 32 bits +// versions of Power. +def : Pat<(atomic_fence (i64 7), (imm)), (SYNC 0)>, Requires<[HasSYNC]>; +def : Pat<(atomic_fence (i32 7), (imm)), (SYNC 0)>, Requires<[HasSYNC]>; +def : Pat<(atomic_fence (imm), (imm)), (SYNC 1)>, Requires<[HasSYNC]>; def : Pat<(atomic_fence (imm), (imm)), (MSYNC)>, Requires<[HasOnlyMSYNC]>; // Additional FNMSUB patterns: -a*c + b == -(a*c - b) diff --git a/llvm/test/CodeGen/PowerPC/atomics-fences.ll b/llvm/test/CodeGen/PowerPC/atomics-fences.ll new file mode 100644 index 00000000000..862bd173fda --- /dev/null +++ b/llvm/test/CodeGen/PowerPC/atomics-fences.ll @@ -0,0 +1,29 @@ +; RUN: llc < %s -mtriple=powerpc-apple-darwin -march=ppc32 -verify-machineinstrs | FileCheck %s --check-prefix=CHECK +; RUN: llc < %s -mtriple=powerpc-apple-darwin -march=ppc64 -verify-machineinstrs | FileCheck %s --check-prefix=CHECK +; RUN: llc < %s -mtriple=powerpc-apple-darwin -mcpu=440 | FileCheck %s --check-prefix=PPC440 + +; Fences +define void @fence_acquire() { +; CHECK-LABEL: fence_acquire +; CHECK: sync 1 +; PPC440-NOT: sync 1 +; PPC440: msync + fence acquire + ret void +} +define void @fence_release() { +; CHECK-LABEL: fence_release +; CHECK: sync 1 +; PPC440-NOT: sync 1 +; PPC440: msync + fence release + ret void +} +define void @fence_seq_cst() { +; CHECK-LABEL: fence_seq_cst +; CHECK: sync 0 +; PPC440-NOT: sync 0 +; PPC440: msync + fence seq_cst + ret void +} |
