Branch fusing
A belated birthday gift for irogers. Fuse cmp-long/if-XXz,
cmp[lg]-[float|double]/if-XXz.
Change-Id: I8fa87f620fcf4e6bcf291bbc7a0ea6c8f5535467
diff --git a/src/compiler/Dataflow.cc b/src/compiler/Dataflow.cc
index 72e3dc4..5f632c0 100644
--- a/src/compiler/Dataflow.cc
+++ b/src/compiler/Dataflow.cc
@@ -801,10 +801,36 @@
// Beginning of extended MIR opcodes
// 100 MIR_PHI
DF_PHI | DF_DA | DF_NULL_TRANSFER_N,
- /*
- * For extended MIR inserted at the MIR2LIR stage, it is okay to have
- * undefined values here.
- */
+
+ // 101 MIR_COPY
+ DF_DA | DF_UB | DF_IS_MOVE,
+
+ // 102 MIR_FUSED_CMPL_FLOAT
+ DF_UA | DF_UB | DF_FP_A | DF_FP_B,
+
+ // 103 MIR_FUSED_CMPG_FLOAT
+ DF_UA | DF_UB | DF_FP_A | DF_FP_B,
+
+ // 104 MIR_FUSED_CMPL_DOUBLE
+ DF_UA_WIDE | DF_UB_WIDE | DF_FP_A | DF_FP_B,
+
+ // 105 MIR_FUSED_CMPG_DOUBLE
+ DF_UA_WIDE | DF_UB_WIDE | DF_FP_A | DF_FP_B,
+
+ // 106 MIR_FUSED_CMP_LONG
+ DF_UA_WIDE | DF_UB_WIDE | DF_CORE_A | DF_CORE_B,
+
+ // 107 MIR_NOP
+ DF_NOP,
+
+ // 108 MIR_NULL_RANGE_UP_CHECK
+ 0,
+
+ // 109 MIR_NULL_RANGE_DOWN_CHECK
+ 0,
+
+ // 110 MIR_LOWER_BOUND
+ 0,
};
/* Return the base virtual register for a SSA name */
@@ -820,6 +846,13 @@
return GET_ELEM_N(cUnit->ssaSubscripts, int, ssaReg);
}
+int getSSAUseCount(CompilationUnit* cUnit, int sReg)
+{
+ DCHECK(sReg < (int)cUnit->rawUseCounts.numUsed);
+ return cUnit->rawUseCounts.elemList[sReg];
+}
+
+
char* oatGetDalvikDisassembly(CompilationUnit* cUnit,
const DecodedInstruction& insn, const char* note)
{
@@ -1827,7 +1860,69 @@
case Instruction::CMPG_FLOAT:
case Instruction::CMPG_DOUBLE:
case Instruction::CMP_LONG:
- // TODO: Check for and fuse preceeding comparison
+ if (mir->next != NULL) {
+ MIR* mirNext = mir->next;
+ Instruction::Code brOpcode = mirNext->dalvikInsn.opcode;
+ ConditionCode ccode = kCondNv;
+ switch(brOpcode) {
+ case Instruction::IF_EQZ:
+ ccode = kCondEq;
+ break;
+ case Instruction::IF_NEZ:
+ // ccode = kCondNe;
+ break;
+ case Instruction::IF_LTZ:
+ // ccode = kCondLt;
+ break;
+ case Instruction::IF_GEZ:
+ // ccode = kCondGe;
+ break;
+ case Instruction::IF_GTZ:
+ // ccode = kCondGt;
+ break;
+ case Instruction::IF_LEZ:
+ // ccode = kCondLe;
+ break;
+ default:
+ break;
+ }
+ // Make sure result of cmp is used by next insn and nowhere else
+ if ((ccode != kCondNv) &&
+ (mir->ssaRep->defs[0] == mirNext->ssaRep->uses[0]) &&
+ (getSSAUseCount(cUnit, mir->ssaRep->defs[0]) == 1)) {
+ mirNext->dalvikInsn.arg[0] = ccode;
+ switch(opcode) {
+ case Instruction::CMPL_FLOAT:
+ mirNext->dalvikInsn.opcode =
+ static_cast<Instruction::Code>(kMirOpFusedCmplFloat);
+ break;
+ case Instruction::CMPL_DOUBLE:
+ mirNext->dalvikInsn.opcode =
+ static_cast<Instruction::Code>(kMirOpFusedCmplDouble);
+ break;
+ case Instruction::CMPG_FLOAT:
+ mirNext->dalvikInsn.opcode =
+ static_cast<Instruction::Code>(kMirOpFusedCmpgFloat);
+ break;
+ case Instruction::CMPG_DOUBLE:
+ mirNext->dalvikInsn.opcode =
+ static_cast<Instruction::Code>(kMirOpFusedCmpgDouble);
+ break;
+ case Instruction::CMP_LONG:
+ mirNext->dalvikInsn.opcode =
+ static_cast<Instruction::Code>(kMirOpFusedCmpLong);
+ break;
+ default: LOG(ERROR) << "Unexpected opcode: " << (int)opcode;
+ }
+ mir->dalvikInsn.opcode = static_cast<Instruction::Code>(kMirOpNop);
+ mirNext->ssaRep->numUses = mir->ssaRep->numUses;
+ mirNext->ssaRep->uses = mir->ssaRep->uses;
+ mirNext->ssaRep->fpUse = mir->ssaRep->fpUse;
+ mirNext->ssaRep->numDefs = 0;
+ mir->ssaRep->numUses = 0;
+ mir->ssaRep->numDefs = 0;
+ }
+ }
break;
default:
break;
@@ -2230,6 +2325,7 @@
for (int i = 0; i < mir->ssaRep->numUses; i++) {
int sReg = mir->ssaRep->uses[i];
DCHECK_LT(sReg, (int)cUnit->useCounts.numUsed);
+ cUnit->rawUseCounts.elemList[sReg]++;
cUnit->useCounts.elemList[sReg] += (1 << weight);
}
if (!(cUnit->disableOpt & (1 << kPromoteCompilerTemps))) {
@@ -2248,6 +2344,7 @@
usesMethodStar &= invokeUsesMethodStar(cUnit, mir);
}
if (usesMethodStar) {
+ cUnit->rawUseCounts.elemList[cUnit->methodSReg]++;
cUnit->useCounts.elemList[cUnit->methodSReg] += (1 << weight);
}
}
@@ -2258,14 +2355,17 @@
void oatMethodUseCount(CompilationUnit *cUnit)
{
- if (cUnit->disableOpt & (1 << kPromoteRegs)) {
- return;
- }
oatInitGrowableList(cUnit, &cUnit->useCounts, cUnit->numSSARegs + 32,
kListMisc);
+ oatInitGrowableList(cUnit, &cUnit->rawUseCounts, cUnit->numSSARegs + 32,
+ kListMisc);
// Initialize list
for (int i = 0; i < cUnit->numSSARegs; i++) {
oatInsertGrowableList(cUnit, &cUnit->useCounts, 0);
+ oatInsertGrowableList(cUnit, &cUnit->rawUseCounts, 0);
+ }
+ if (cUnit->disableOpt & (1 << kPromoteRegs)) {
+ return;
}
oatDataFlowAnalysisDispatcher(cUnit, countUses,
kAllNodes, false /* isIterative */);