uint32_t
OptimizationInfo::compilerWarmUpThreshold(JSScript *script, jsbytecode *pc) const
{
JS_ASSERT(pc == nullptr || pc == script->code() || JSOp(*pc) == JSOP_LOOPENTRY);
if (pc == script->code())
pc = nullptr;
uint32_t warmUpThreshold = compilerWarmUpThreshold_;
if (js_JitOptions.forceDefaultIonWarmUpThreshold)
warmUpThreshold = js_JitOptions.forcedDefaultIonWarmUpThreshold;
// If the script is too large to compile on the main thread, we can still
// compile it off thread. In these cases, increase the warm-up counter
// threshold to improve the compilation's type information and hopefully
// avoid later recompilation.
if (script->length() > MAX_MAIN_THREAD_SCRIPT_SIZE)
warmUpThreshold *= (script->length() / (double) MAX_MAIN_THREAD_SCRIPT_SIZE);
uint32_t numLocalsAndArgs = NumLocalsAndArgs(script);
if (numLocalsAndArgs > MAX_MAIN_THREAD_LOCALS_AND_ARGS)
warmUpThreshold *= (numLocalsAndArgs / (double) MAX_MAIN_THREAD_LOCALS_AND_ARGS);
if (!pc || js_JitOptions.eagerCompilation)
return warmUpThreshold;
// It's more efficient to enter outer loops, rather than inner loops, via OSR.
// To accomplish this, we use a slightly higher threshold for inner loops.
// Note that the loop depth is always > 0 so we will prefer non-OSR over OSR.
uint32_t loopDepth = LoopEntryDepthHint(pc);
JS_ASSERT(loopDepth > 0);
return warmUpThreshold + loopDepth * 100;
}
bool
LCovSource::writeScript(JSScript* script)
{
numFunctionsFound_++;
outFN_.printf("FN:%d,", script->lineno());
if (!writeScriptName(outFN_, script))
return false;
outFN_.put("\n", 1);
uint64_t hits = 0;
ScriptCounts* sc = nullptr;
if (script->hasScriptCounts()) {
sc = &script->getScriptCounts();
numFunctionsHit_++;
const PCCounts* counts = sc->maybeGetPCCounts(script->pcToOffset(script->main()));
outFNDA_.printf("FNDA:%" PRIu64 ",", counts->numExec());
if (!writeScriptName(outFNDA_, script))
return false;
outFNDA_.put("\n", 1);
// Set the hit count of the pre-main code to 1, if the function ever got
// visited.
hits = 1;
}
jsbytecode* snpc = script->code();
jssrcnote* sn = script->notes();
if (!SN_IS_TERMINATOR(sn))
snpc += SN_DELTA(sn);
size_t lineno = script->lineno();
jsbytecode* end = script->codeEnd();
size_t branchId = 0;
size_t tableswitchExitOffset = 0;
for (jsbytecode* pc = script->code(); pc != end; pc = GetNextPc(pc)) {
JSOp op = JSOp(*pc);
bool jump = IsJumpOpcode(op) || op == JSOP_TABLESWITCH;
bool fallsthrough = BytecodeFallsThrough(op) && op != JSOP_GOSUB;
// If the current script & pc has a hit-count report, then update the
// current number of hits.
if (sc) {
const PCCounts* counts = sc->maybeGetPCCounts(script->pcToOffset(pc));
if (counts)
hits = counts->numExec();
}
// If we have additional source notes, walk all the source notes of the
// current pc.
if (snpc <= pc) {
size_t oldLine = lineno;
while (!SN_IS_TERMINATOR(sn) && snpc <= pc) {
SrcNoteType type = (SrcNoteType) SN_TYPE(sn);
if (type == SRC_SETLINE)
lineno = size_t(GetSrcNoteOffset(sn, 0));
else if (type == SRC_NEWLINE)
lineno++;
else if (type == SRC_TABLESWITCH)
tableswitchExitOffset = GetSrcNoteOffset(sn, 0);
sn = SN_NEXT(sn);
snpc += SN_DELTA(sn);
}
if (oldLine != lineno && fallsthrough) {
outDA_.printf("DA:%d,%" PRIu64 "\n", lineno, hits);
// Count the number of lines instrumented & hit.
numLinesInstrumented_++;
if (hits)
numLinesHit_++;
}
}
// If the current instruction has thrown, then decrement the hit counts
// with the number of throws.
if (sc) {
const PCCounts* counts = sc->maybeGetThrowCounts(script->pcToOffset(pc));
if (counts)
hits -= counts->numExec();
}
// If the current pc corresponds to a conditional jump instruction, then reports
// branch hits.
if (jump && fallsthrough) {
jsbytecode* fallthroughTarget = GetNextPc(pc);
uint64_t fallthroughHits = 0;
if (sc) {
const PCCounts* counts = sc->maybeGetPCCounts(script->pcToOffset(fallthroughTarget));
if (counts)
fallthroughHits = counts->numExec();
}
uint64_t taken = hits - fallthroughHits;
outBRDA_.printf("BRDA:%d,%d,0,", lineno, branchId);
if (taken)
outBRDA_.printf("%d\n", taken);
else
outBRDA_.put("-\n", 2);
outBRDA_.printf("BRDA:%d,%d,1,", lineno, branchId);
if (fallthroughHits)
outBRDA_.printf("%d\n", fallthroughHits);
else
outBRDA_.put("-\n", 2);
// Count the number of branches, and the number of branches hit.
numBranchesFound_ += 2;
if (hits)
numBranchesHit_ += !!taken + !!fallthroughHits;
branchId++;
}
// If the current pc corresponds to a pre-computed switch case, then
// reports branch hits for each case statement.
if (jump && op == JSOP_TABLESWITCH) {
MOZ_ASSERT(tableswitchExitOffset != 0);
// Get the default and exit pc
jsbytecode* exitpc = pc + tableswitchExitOffset;
jsbytecode* defaultpc = pc + GET_JUMP_OFFSET(pc);
MOZ_ASSERT(defaultpc > pc && defaultpc <= exitpc);
// Get the low and high from the tableswitch
int32_t low = GET_JUMP_OFFSET(pc + JUMP_OFFSET_LEN * 1);
int32_t high = GET_JUMP_OFFSET(pc + JUMP_OFFSET_LEN * 2);
MOZ_ASSERT(high - low + 1 >= 0);
size_t numCases = high - low + 1;
jsbytecode* jumpTable = pc + JUMP_OFFSET_LEN * 3;
jsbytecode* firstcasepc = exitpc;
for (size_t j = 0; j < numCases; j++) {
jsbytecode* testpc = pc + GET_JUMP_OFFSET(jumpTable + JUMP_OFFSET_LEN * j);
if (testpc < firstcasepc)
firstcasepc = testpc;
}
// Count the number of hits of the default branch, by subtracting
// the number of hits of each cases.
uint64_t defaultHits = hits;
// Count the number of hits of the previous case entry.
uint64_t fallsThroughHits = 0;
// Record branches for each cases.
size_t caseId = 0;
for (size_t i = 0; i < numCases; i++) {
jsbytecode* casepc = pc + GET_JUMP_OFFSET(jumpTable + JUMP_OFFSET_LEN * i);
// The case is not present, and jumps to the default pc if used.
if (casepc == pc)
continue;
// PCs might not be in increasing order of case indexes.
jsbytecode* lastcasepc = firstcasepc - 1;
for (size_t j = 0; j < numCases; j++) {
jsbytecode* testpc = pc + GET_JUMP_OFFSET(jumpTable + JUMP_OFFSET_LEN * j);
if (lastcasepc < testpc && (testpc < casepc || (j < i && testpc == casepc)))
lastcasepc = testpc;
}
if (casepc != lastcasepc) {
// Case (i + low)
uint64_t caseHits = 0;
if (sc) {
const PCCounts* counts = sc->maybeGetPCCounts(script->pcToOffset(casepc));
if (counts)
caseHits = counts->numExec();
// Remove fallthrough.
fallsThroughHits = 0;
if (casepc != firstcasepc) {
jsbytecode* endpc = lastcasepc;
while (GetNextPc(endpc) < casepc)
endpc = GetNextPc(endpc);
if (BytecodeFallsThrough(JSOp(*endpc)))
fallsThroughHits = script->getHitCount(endpc);
}
caseHits -= fallsThroughHits;
}
outBRDA_.printf("BRDA:%d,%d,%d,", lineno, branchId, caseId);
if (caseHits)
outBRDA_.printf("%d\n", caseHits);
else
outBRDA_.put("-\n", 2);
numBranchesFound_++;
numBranchesHit_ += !!caseHits;
defaultHits -= caseHits;
caseId++;
}
}
// Compute the number of hits of the default branch, if it has its
// own case clause.
bool defaultHasOwnClause = true;
if (defaultpc != exitpc) {
defaultHits = 0;
// Look for the last case entry before the default pc.
jsbytecode* lastcasepc = firstcasepc - 1;
for (size_t j = 0; j < numCases; j++) {
jsbytecode* testpc = pc + GET_JUMP_OFFSET(jumpTable + JUMP_OFFSET_LEN * j);
if (lastcasepc < testpc && testpc <= defaultpc)
lastcasepc = testpc;
}
if (lastcasepc == defaultpc)
defaultHasOwnClause = false;
// Look if the last case entry fallthrough to the default case,
// in which case we have to remove the number of fallthrough
// hits out of the default case hits.
if (sc && lastcasepc != pc) {
jsbytecode* endpc = lastcasepc;
while (GetNextPc(endpc) < defaultpc)
endpc = GetNextPc(endpc);
if (BytecodeFallsThrough(JSOp(*endpc)))
fallsThroughHits = script->getHitCount(endpc);
}
if (sc) {
const PCCounts* counts = sc->maybeGetPCCounts(script->pcToOffset(defaultpc));
if (counts)
defaultHits = counts->numExec();
}
defaultHits -= fallsThroughHits;
}
if (defaultHasOwnClause) {
outBRDA_.printf("BRDA:%d,%d,%d,", lineno, branchId, caseId);
if (defaultHits)
outBRDA_.printf("%d\n", defaultHits);
else
outBRDA_.put("-\n", 2);
numBranchesFound_++;
numBranchesHit_ += !!defaultHits;
}
// Increment the branch identifier, and go to the next instruction.
branchId++;
tableswitchExitOffset = 0;
}
}
// Report any new OOM.
if (outFN_.hadOutOfMemory() ||
outFNDA_.hadOutOfMemory() ||
outBRDA_.hadOutOfMemory() ||
outDA_.hadOutOfMemory())
{
return false;
}
// If this script is the top-level script, then record it such that we can
// assume that the code coverage report is complete, as this script has
// references on all inner scripts.
if (script->isTopLevel())
hasTopLevelScript_ = true;
return true;
}
