Aligned bundling support. Following the discussion here:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-December/056754.html
The proposal and implementation are fully documented here:
https://sites.google.com/a/chromium.org/dev/nativeclient/pnacl/aligned-bundling-support-in-llvm
Tests will follow shortly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170718 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/MC/MCObjectStreamer.cpp b/lib/MC/MCObjectStreamer.cpp
index 4d6900f..e36e181 100644
--- a/lib/MC/MCObjectStreamer.cpp
+++ b/lib/MC/MCObjectStreamer.cpp
@@ -180,21 +180,27 @@
if (Inst.getOperand(i).isExpr())
AddValueSymbols(Inst.getOperand(i).getExpr());
- getCurrentSectionData()->setHasInstructions(true);
+ MCSectionData *SD = getCurrentSectionData();
+ SD->setHasInstructions(true);
// Now that a machine instruction has been assembled into this section, make
// a line entry for any .loc directive that has been seen.
MCLineEntry::Make(this, getCurrentSection());
// If this instruction doesn't need relaxation, just emit it as data.
- if (!getAssembler().getBackend().mayNeedRelaxation(Inst)) {
+ MCAssembler &Assembler = getAssembler();
+ if (!Assembler.getBackend().mayNeedRelaxation(Inst)) {
EmitInstToData(Inst);
return;
}
- // Otherwise, if we are relaxing everything, relax the instruction as much as
- // possible and emit it as data.
- if (getAssembler().getRelaxAll()) {
+ // Otherwise, relax and emit it as data if either:
+ // - The RelaxAll flag was passed
+ // - Bundling is enabled and this instruction is inside a bundle-locked
+ // group. We want to emit all such instructions into the same data
+ // fragment.
+ if (Assembler.getRelaxAll() ||
+ (Assembler.isBundlingEnabled() && SD->isBundleLocked())) {
MCInst Relaxed;
getAssembler().getBackend().relaxInstruction(Inst, Relaxed);
while (getAssembler().getBackend().mayNeedRelaxation(Relaxed))
@@ -208,6 +214,8 @@
}
void MCObjectStreamer::EmitInstToFragment(const MCInst &Inst) {
+ // Always create a new, separate fragment here, because its size can change
+ // during relaxation.
MCInstFragment *IF = new MCInstFragment(Inst, getCurrentSectionData());
SmallString<128> Code;
@@ -217,6 +225,21 @@
IF->getContents().append(Code.begin(), Code.end());
}
+const char *BundlingNotImplementedMsg =
+ "Aligned bundling is not implemented for this object format";
+
+void MCObjectStreamer::EmitBundleAlignMode(unsigned AlignPow2) {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitBundleLock() {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
+void MCObjectStreamer::EmitBundleUnlock() {
+ llvm_unreachable(BundlingNotImplementedMsg);
+}
+
void MCObjectStreamer::EmitDwarfAdvanceLineAddr(int64_t LineDelta,
const MCSymbol *LastLabel,
const MCSymbol *Label,