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Diffstat (limited to 'vm/compiler/codegen/arm/LocalOptimizations.c')
-rw-r--r--vm/compiler/codegen/arm/LocalOptimizations.c168
1 files changed, 153 insertions, 15 deletions
diff --git a/vm/compiler/codegen/arm/LocalOptimizations.c b/vm/compiler/codegen/arm/LocalOptimizations.c
index 11aaeddaf..fbc0e26f1 100644
--- a/vm/compiler/codegen/arm/LocalOptimizations.c
+++ b/vm/compiler/codegen/arm/LocalOptimizations.c
@@ -39,6 +39,28 @@ static inline bool isDalvikStore(ArmLIR *lir)
(lir->opCode == THUMB2_VSTRD)));
}
+/* Double regs overlap float regs. Return true if collision */
+static bool regClobber(int reg1, int reg2)
+{
+ int reg1a, reg1b;
+ int reg2a, reg2b;
+ if (!FPREG(reg1) || !FPREG(reg2))
+ return (reg1 == reg2);
+ if (DOUBLEREG(reg1)) {
+ reg1a = reg1 & FP_REG_MASK;
+ reg1b = reg1a + 1;
+ } else {
+ reg1a = reg1b = reg1 & FP_REG_MASK;
+ }
+ if (DOUBLEREG(reg2)) {
+ reg2a = reg2 & FP_REG_MASK;
+ reg2b = reg2a + 1;
+ } else {
+ reg2a = reg2b = reg2 & FP_REG_MASK;
+ }
+ return (reg1a == reg2a) || (reg1a == reg2b) ||
+ (reg1b == reg2a) || (reg1b == reg2b);
+}
/*
* Perform a pass of top-down walk to
* 1) Eliminate redundant loads and stores
@@ -63,6 +85,11 @@ static void applyLoadStoreElimination(CompilationUnit *cUnit,
int nativeRegId = thisLIR->operands[0];
ArmLIR *checkLIR;
int sinkDistance = 0;
+ /*
+ * Add r15 (pc) to the mask to prevent this instruction
+ * from sinking past branch instructions.
+ */
+ u8 stopMask = ENCODE_GP_REG(rpc) | thisLIR->useMask;
for (checkLIR = NEXT_LIR(thisLIR);
checkLIR != tailLIR;
@@ -100,7 +127,7 @@ static void applyLoadStoreElimination(CompilationUnit *cUnit,
bool stopHere = false;
/* Last instruction reached */
- stopHere |= checkLIR->generic.next == NULL;
+ stopHere |= NEXT_LIR(checkLIR) == tailLIR;
/*
* Conservatively assume there is a memory dependency
@@ -110,24 +137,19 @@ static void applyLoadStoreElimination(CompilationUnit *cUnit,
checkLIR->opCode == THUMB_LDMIA ||
checkLIR->opCode == THUMB_STR_RRR ||
checkLIR->opCode == THUMB_LDR_RRR ||
+ checkLIR->opCode == THUMB2_STR_RRR ||
+ checkLIR->opCode == THUMB2_LDR_RRR ||
+ checkLIR->opCode == THUMB2_STMIA ||
+ checkLIR->opCode == THUMB2_LDMIA ||
checkLIR->opCode == THUMB2_VLDRD ||
checkLIR->opCode == THUMB2_VSTRD;
-;
-
- if (!isPseudoOpCode(checkLIR->opCode)) {
- /* Store data is clobbered */
- stopHere |= (EncodingMap[checkLIR->opCode].flags &
- CLOBBER_DEST) != 0 &&
- checkLIR->operands[0] == nativeRegId;
- stopHere |= (EncodingMap[checkLIR->opCode].flags &
- IS_BRANCH) != 0;
- }
+ /* Store data is clobbered */
+ stopHere |= (stopMask & checkLIR->defMask) != 0;
/* Found a new place to put the store - move it here */
if (stopHere == true) {
-
/* The store can be sunk for at least one cycle */
if (sinkDistance != 0) {
ArmLIR *newStoreLIR =
@@ -157,10 +179,126 @@ static void applyLoadStoreElimination(CompilationUnit *cUnit,
}
}
+static void applyLoadHoisting(CompilationUnit *cUnit,
+ ArmLIR *headLIR,
+ ArmLIR *tailLIR)
+{
+ ArmLIR *thisLIR;
+
+ cUnit->optRound++;
+ for (thisLIR = headLIR;
+ thisLIR != tailLIR;
+ thisLIR = NEXT_LIR(thisLIR)) {
+ /* Skip newly added instructions */
+ if (thisLIR->age >= cUnit->optRound ||
+ thisLIR->isNop == true) {
+ continue;
+ }
+ if (isDalvikLoad(thisLIR)) {
+ int dRegId = thisLIR->operands[2];
+ int nativeRegId = thisLIR->operands[0];
+ ArmLIR *checkLIR;
+ int hoistDistance = 0;
+ u8 stopUseMask = ENCODE_GP_REG(rpc) | thisLIR->useMask;
+ u8 stopDefMask = thisLIR->defMask;
+
+ for (checkLIR = PREV_LIR(thisLIR);
+ checkLIR != headLIR;
+ checkLIR = PREV_LIR(checkLIR)) {
+
+ if (checkLIR->isNop) continue;
+
+ /* Check if the current load is redundant */
+ if ((isDalvikLoad(checkLIR) || isDalvikStore(checkLIR)) &&
+ checkLIR->operands[2] == dRegId ) {
+ if (FPREG(nativeRegId) != FPREG(checkLIR->operands[0])) {
+ break; // TODO: handle gen<=>float copies
+ }
+ /* Insert a move to replace the load */
+ if (checkLIR->operands[0] != nativeRegId) {
+ ArmLIR *moveLIR;
+ moveLIR = dvmCompilerRegCopy(cUnit,
+ nativeRegId,
+ checkLIR->operands[0]);
+ /*
+ * Convert *thisLIR* load into a move
+ */
+ dvmCompilerInsertLIRAfter((LIR *) checkLIR,
+ (LIR *) moveLIR);
+ }
+ cUnit->printMe = true;
+ thisLIR->isNop = true;
+ break;
+
+ /* Find out if the load can be yanked past the checkLIR */
+ } else {
+ bool stopHere = false;
+
+ /* Last instruction reached */
+ stopHere |= PREV_LIR(checkLIR) == headLIR;
+
+ /*
+ * Conservatively assume there is a memory dependency
+ * for st/ld multiples and reg+reg address mode
+ */
+ stopHere |= checkLIR->opCode == THUMB_STMIA ||
+ checkLIR->opCode == THUMB_LDMIA ||
+ checkLIR->opCode == THUMB_STR_RRR ||
+ checkLIR->opCode == THUMB_LDR_RRR ||
+ checkLIR->opCode == THUMB2_STR_RRR ||
+ checkLIR->opCode == THUMB2_LDR_RRR ||
+ checkLIR->opCode == THUMB2_STMIA ||
+ checkLIR->opCode == THUMB2_LDMIA ||
+ checkLIR->opCode == THUMB2_VLDRD ||
+ checkLIR->opCode == THUMB2_VSTRD;
+
+ /* Base address is clobbered by checkLIR */
+ stopHere |= (stopUseMask & checkLIR->defMask) != 0;
+
+ /* Load target clobbers use/def in checkLIR */
+ stopHere |= (stopDefMask &
+ (checkLIR->useMask | checkLIR->defMask)) != 0;
+
+ /* Found a new place to put the load - move it here */
+ if (stopHere == true) {
+ /* The store can be hoisted for at least one cycle */
+ if (hoistDistance != 0) {
+ ArmLIR *newLoadLIR =
+ dvmCompilerNew(sizeof(ArmLIR), true);
+ *newLoadLIR = *thisLIR;
+ newLoadLIR->age = cUnit->optRound;
+ /*
+ * Insertion is guaranteed to succeed since checkLIR
+ * is never the first LIR on the list
+ */
+ dvmCompilerInsertLIRAfter((LIR *) checkLIR,
+ (LIR *) newLoadLIR);
+ thisLIR->isNop = true;
+ cUnit->printMe = true;
+ }
+ break;
+ }
+
+ /*
+ * Saw a real instruction that the store can be sunk after
+ */
+ if (!isPseudoOpCode(checkLIR->opCode)) {
+ hoistDistance++;
+ }
+ }
+ }
+ }
+ }
+}
+
void dvmCompilerApplyLocalOptimizations(CompilationUnit *cUnit, LIR *headLIR,
LIR *tailLIR)
{
- applyLoadStoreElimination(cUnit,
- (ArmLIR *) headLIR,
- (ArmLIR *) tailLIR);
+ if (!(gDvmJit.disableOpt & (1 << kLoadStoreElimination))) {
+ applyLoadStoreElimination(cUnit, (ArmLIR *) headLIR,
+ (ArmLIR *) tailLIR);
+ }
+ if (!(gDvmJit.disableOpt & (1 << kLoadHoisting))) {
+ applyLoadHoisting(cUnit, (ArmLIR *) headLIR, (ArmLIR *) tailLIR);
+ }
}
generated by cgit v1.2.3 (git 2.25.1) at 2025-12-22 14:48:25 +0000