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swiftshader
Commit 4175b2a6 by Jim Stichnoth
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Subzero: Also dump live-end info for stack vars under -asm-verbose.

It's sometimes useful to know whether a use of a stack variable (as opposed to a physical register) is the last use of that variable. For example, in a code sequence like: movl %edx, 24(%esp) movl 24(%esp), %edx it would be nice to know whether the code sequence is merely bad (i.e., 24(%esp) will be used later), or horrible (i.e., this ends 24(%esp)'s live range). We add stack variables to the per-instruction live-range-end annotation, but not to the per-block live-in and live-out annotations, because the latter would clutter the output greatly while adding very little actionable information. BUG= https://code.google.com/p/nativeclient/issues/detail?id=4135 R=jvoung@chromium.org Review URL: https://codereview.chromium.org/1113133002
parent 76dcf1a8
Showing with 16 additions and 13 deletions
src/IceCfgNode.cpp
......@@ -824,15 +824,14 @@ void emitLiveRangesEnded(Ostream &Str, const Cfg *Func, const Inst *Instr,
SizeT NumVars = Src->getNumVars();
for (SizeT J = 0; J < NumVars; ++J) {
const Variable *Var = Src->getVar(J);
if (Var->hasReg()) {
if (Instr->isLastUse(Var) && --LiveRegCount[Var->getRegNum()] == 0) {
if (First)
Str << " \t# END=";
else
Str << ",";
Var->emit(Func);
First = false;
}
if (Instr->isLastUse(Var) &&
(!Var->hasReg() || --LiveRegCount[Var->getRegNum()] == 0)) {
if (First)
Str << " \t# END=";
else
Str << ",";
Var->emit(Func);
First = false;
}
}
}
......@@ -870,8 +869,10 @@ void CfgNode::emit(Cfg *Func) const {
Liveness && Func->getContext()->getFlags().getDecorateAsm();
Str << getAsmName() << ":\n";
std::vector<SizeT> LiveRegCount(Func->getTarget()->getNumRegisters());
if (DecorateAsm)
emitRegisterUsage(Str, Func, this, true, LiveRegCount);
if (DecorateAsm) {
const bool IsLiveIn = true;
emitRegisterUsage(Str, Func, this, IsLiveIn, LiveRegCount);
}
for (const Inst &I : Phis) {
if (I.isDeleted())
......@@ -894,8 +895,10 @@ void CfgNode::emit(Cfg *Func) const {
Str << "\n";
updateStats(Func, &I);
}
if (DecorateAsm)
emitRegisterUsage(Str, Func, this, false, LiveRegCount);
if (DecorateAsm) {
const bool IsLiveIn = false;
emitRegisterUsage(Str, Func, this, IsLiveIn, LiveRegCount);
}
}
// Helper class for emitIAS().
......
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