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authorSanjay Patel <spatel@rotateright.com>2016-05-20 17:07:19 +0000
committerSanjay Patel <spatel@rotateright.com>2016-05-20 17:07:19 +0000
commit2c98ad1c24791aa0f95744f9cb006dc8d4dbe4ad (patch)
tree0e309ae9bc070030f1524be67cbee443f9f0bb25
parent6d605e9529264077a1349d5c76f7de052cd8bcf9 (diff)
fix comments; NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@270237 91177308-0d34-0410-b5e6-96231b3b80d8
-rw-r--r--lib/Target/X86/X86VZeroUpper.cpp17
1 files changed, 8 insertions, 9 deletions
diff --git a/lib/Target/X86/X86VZeroUpper.cpp b/lib/Target/X86/X86VZeroUpper.cpp
index fc0bce45bd9..2d053a65a44 100644
--- a/lib/Target/X86/X86VZeroUpper.cpp
+++ b/lib/Target/X86/X86VZeroUpper.cpp
@@ -176,7 +176,7 @@ void VZeroUpperInserter::addDirtySuccessor(MachineBasicBlock &MBB) {
/// instructions before function calls.
void VZeroUpperInserter::processBasicBlock(MachineBasicBlock &MBB) {
- // Start by assuming that the block PASS_THROUGH, which implies no unguarded
+ // Start by assuming that the block is PASS_THROUGH which implies no unguarded
// calls.
BlockExitState CurState = PASS_THROUGH;
BlockStates[MBB.getNumber()].FirstUnguardedCall = MBB.end();
@@ -212,12 +212,11 @@ void VZeroUpperInserter::processBasicBlock(MachineBasicBlock &MBB) {
if (MI->isCall() && !callClobbersAnyYmmReg(MI))
continue;
- // The VZEROUPPER instruction resets the upper 128 bits of all Intel AVX
- // registers. This instruction has zero latency. In addition, the processor
- // changes back to Clean state, after which execution of Intel SSE
- // instructions or Intel AVX instructions has no transition penalty. Add
- // the VZEROUPPER instruction before any function call/return that might
- // execute SSE code.
+ // The VZEROUPPER instruction resets the upper 128 bits of all AVX
+ // registers. In addition, the processor changes back to Clean state, after
+ // which execution of SSE instructions or AVX instructions has no transition
+ // penalty. Add the VZEROUPPER instruction before any function call/return
+ // that might execute SSE code.
// FIXME: In some cases, we may want to move the VZEROUPPER into a
// predecessor block.
if (CurState == EXITS_DIRTY) {
@@ -290,7 +289,7 @@ bool VZeroUpperInserter::runOnMachineFunction(MachineFunction &MF) {
for (MachineBasicBlock &MBB : MF)
processBasicBlock(MBB);
- // If any YMM regs are live in to this function, add the entry block to the
+ // If any YMM regs are live-in to this function, add the entry block to the
// DirtySuccessors list
if (FnHasLiveInYmm)
addDirtySuccessor(MF.front());
@@ -308,7 +307,7 @@ bool VZeroUpperInserter::runOnMachineFunction(MachineFunction &MF) {
if (BBState.FirstUnguardedCall != MBB.end())
insertVZeroUpper(BBState.FirstUnguardedCall, MBB);
- // If this successor was a pass-through block then it is now dirty, and its
+ // If this successor was a pass-through block, then it is now dirty. Its
// successors need to be added to the worklist (if they haven't been
// already).
if (BBState.ExitState == PASS_THROUGH) {