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authorEvan Cheng <evan.cheng@apple.com>2011-01-07 23:50:32 +0000
committerEvan Cheng <evan.cheng@apple.com>2011-01-07 23:50:32 +0000
commitc36b7069b42bece963b7e6adf020353ce990ef76 (patch)
treefdbe6e1cede36ae3485403b9165bfdc039056eeb /lib/CodeGen/VirtRegRewriter.cpp
parent067a16c974fef473fd3bca1d58db0d50c59882ce (diff)
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Do not model all INLINEASM instructions as having unmodelled side effects.
Instead encode llvm IR level property "HasSideEffects" in an operand (shared with IsAlignStack). Added MachineInstrs::hasUnmodeledSideEffects() to check the operand when the instruction is an INLINEASM. This allows memory instructions to be moved around INLINEASM instructions. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@123044 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/VirtRegRewriter.cpp')
-rw-r--r--lib/CodeGen/VirtRegRewriter.cpp11
1 files changed, 9 insertions, 2 deletions
diff --git a/lib/CodeGen/VirtRegRewriter.cpp b/lib/CodeGen/VirtRegRewriter.cpp
index d04b9285ba..87781067ef 100644
--- a/lib/CodeGen/VirtRegRewriter.cpp
+++ b/lib/CodeGen/VirtRegRewriter.cpp
@@ -1620,9 +1620,16 @@ static bool isSafeToDelete(MachineInstr &MI) {
const TargetInstrDesc &TID = MI.getDesc();
if (TID.mayLoad() || TID.mayStore() || TID.isCall() || TID.isTerminator() ||
TID.isCall() || TID.isBarrier() || TID.isReturn() ||
- TID.hasUnmodeledSideEffects() ||
- MI.isLabel() || MI.isDebugValue())
+ MI.isLabel() || MI.isDebugValue() ||
+ MI.hasUnmodeledSideEffects())
return false;
+
+ // Technically speaking inline asm without side effects and no defs can still
+ // be deleted. But there is so much bad inline asm code out there, we should
+ // let them be.
+ if (MI.isInlineAsm())
+ return false;
+
for (unsigned i = 0, e = MI.getNumOperands(); i != e; ++i) {
MachineOperand &MO = MI.getOperand(i);
if (!MO.isReg() || !MO.getReg())