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authorDan Gohman <gohman@apple.com>2010-05-13 19:24:00 +0000
committerDan Gohman <gohman@apple.com>2010-05-13 19:24:00 +0000
commit49b4589978ca181537c8ae694ac4c8d58d27a09a (patch)
tree4ce239768a2457c5c072f64be5f7889343988370 /lib/CodeGen/MachineRegisterInfo.cpp
parente1308d86ed2402483aa9d056af531fd773e1121f (diff)
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Add a utility function for conservatively clearing kill flags, and make
use of it in MachineCSE. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@103726 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'lib/CodeGen/MachineRegisterInfo.cpp')
-rw-r--r--lib/CodeGen/MachineRegisterInfo.cpp9
1 files changed, 9 insertions, 0 deletions
diff --git a/lib/CodeGen/MachineRegisterInfo.cpp b/lib/CodeGen/MachineRegisterInfo.cpp
index 5465fca05f..402be479ea 100644
--- a/lib/CodeGen/MachineRegisterInfo.cpp
+++ b/lib/CodeGen/MachineRegisterInfo.cpp
@@ -133,6 +133,15 @@ bool MachineRegisterInfo::hasOneNonDBGUse(unsigned RegNo) const {
return ++UI == use_nodbg_end();
}
+/// clearKillFlags - Iterate over all the uses of the given register and
+/// clear the kill flag from the MachineOperand. This function is used by
+/// optimization passes which extend register lifetimes and need only
+/// preserve conservative kill flag information.
+void MachineRegisterInfo::clearKillFlags(unsigned Reg) const {
+ for (use_iterator UI = use_begin(Reg), UE = use_end(); UI != UE; ++UI)
+ UI.getOperand().setIsKill(false);
+}
+
bool MachineRegisterInfo::isLiveIn(unsigned Reg) const {
for (livein_iterator I = livein_begin(), E = livein_end(); I != E; ++I)
if (I->first == Reg || I->second == Reg)