[PATCH] D19885: [AArch64] Decouple zero store promotion from narrow ld merge. NFC.
Jun Bum Lim via llvm-commits
llvm-commits at lists.llvm.org
Tue May 3 12:52:45 PDT 2016
junbuml created this revision.
junbuml added reviewers: mcrosier, jmolloy, t.p.northover.
junbuml added a subscriber: llvm-commits.
Herald added subscribers: mcrosier, rengolin, aemerson.
This change refactors to decouple the zero store promotion from the narrow ld merge and add a flag (enable-narrow-ld-merge=true) to control the narrow ld merge optimization.
http://reviews.llvm.org/D19885
Files:
lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
Index: lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
===================================================================
--- lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
+++ lib/Target/AArch64/AArch64LoadStoreOptimizer.cpp
@@ -51,6 +51,10 @@
static cl::opt<unsigned> UpdateLimit("aarch64-update-scan-limit", cl::init(100),
cl::Hidden);
+static cl::opt<bool> EnableNarrowLdMerge("enable-narrow-ld-merge", cl::Hidden,
+ cl::init(true),
+ cl::desc("Enable narrow load merge"));
+
namespace llvm {
void initializeAArch64LoadStoreOptPass(PassRegistry &);
}
@@ -614,11 +618,14 @@
(UnscaledLdOffset + LoadSize <= (UnscaledStOffset + StoreSize));
}
-static bool isPromotableZeroStoreOpcode(MachineInstr *MI) {
- unsigned Opc = MI->getOpcode();
+static bool isPromotableZeroStoreOpcode(unsigned Opc) {
return isNarrowStore(Opc) || Opc == AArch64::STRWui || Opc == AArch64::STURWi;
}
+static bool isPromotableZeroStoreOpcode(MachineInstr *MI) {
+ return isPromotableZeroStoreOpcode(MI->getOpcode());
+}
+
static bool isPromotableZeroStoreInst(MachineInstr *MI) {
return (isPromotableZeroStoreOpcode(MI)) &&
getLdStRegOp(MI).getReg() == AArch64::WZR;
@@ -1722,36 +1729,17 @@
for (MachineBasicBlock::iterator MBBI = MBB.begin(), E = MBB.end();
enableNarrowLdOpt && MBBI != E;) {
MachineInstr *MI = MBBI;
- switch (MI->getOpcode()) {
- default:
- // Just move on to the next instruction.
- ++MBBI;
- break;
- // Scaled instructions.
- case AArch64::LDRBBui:
- case AArch64::LDRHHui:
- case AArch64::LDRSBWui:
- case AArch64::LDRSHWui:
- case AArch64::STRBBui:
- case AArch64::STRHHui:
- case AArch64::STRWui:
- // Unscaled instructions.
- case AArch64::LDURBBi:
- case AArch64::LDURHHi:
- case AArch64::LDURSBWi:
- case AArch64::LDURSHWi:
- case AArch64::STURBBi:
- case AArch64::STURHHi:
- case AArch64::STURWi: {
+ unsigned Opc = MI->getOpcode();
+ if (isPromotableZeroStoreOpcode(Opc) ||
+ (EnableNarrowLdMerge && isNarrowLoad(Opc))) {
if (tryToMergeLdStInst(MBBI)) {
Modified = true;
- break;
- }
+ } else
+ ++MBBI;
+ } else
++MBBI;
- break;
- }
- }
}
+
// 3) Find loads and stores that can be merged into a single load or store
// pair instruction.
// e.g.,
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