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Fix JitDisasmWithAlignmentBoundaries (#84827)
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@EgorBo
EgorBo authored Apr 17, 2023
1 parent c1b7a9f commit e121d77
Showing 1 changed file with 104 additions and 92 deletions.
196 changes: 104 additions & 92 deletions src/coreclr/jit/emit.cpp
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Original file line number Diff line number Diff line change
Expand Up @@ -7145,129 +7145,141 @@ unsigned emitter::emitEndCodeGen(Compiler* comp,

emitCurIG = ig;

for (unsigned cnt = ig->igInsCnt; cnt > 0; cnt--)
// Fast loop without any JitDisasm/JitDump TP overhead
if (!emitComp->opts.disAsm INDEBUG(&&!emitComp->verbose))
{
#ifdef DEBUG
if ((emitComp->opts.disAsm || emitComp->verbose) && (JitConfig.JitDisasmWithDebugInfo() != 0) &&
(id->idCodeSize() > 0))
for (unsigned cnt = ig->igInsCnt; cnt > 0; cnt--)
{
UNATIVE_OFFSET curCodeOffs = emitCurCodeOffs(cp);
while (nextMapping != emitComp->genRichIPmappings.end())
{
UNATIVE_OFFSET mappingOffs = nextMapping->nativeLoc.CodeOffset(this);

if (mappingOffs > curCodeOffs)
{
// Still haven't reached instruction that next mapping belongs to.
break;
}

// We reached the mapping or went past it.
if (mappingOffs == curCodeOffs)
{
emitDispInsIndent();
printf("; ");
nextMapping->debugInfo.Dump(true);
printf("\n");
}

++nextMapping;
}
size_t curInstrAddr = (size_t)cp;
instrDesc* curInstrDesc = id;
size_t insSize = emitIssue1Instr(ig, id, &cp);
emitAdvanceInstrDesc(&id, insSize);
}
#endif
size_t insSize = emitIssue1Instr(ig, id, &cp);
emitAdvanceInstrDesc(&id, insSize);
}

// Print the alignment boundary
if ((emitComp->opts.disAsm INDEBUG(|| emitComp->verbose)) &&
(INDEBUG(emitComp->opts.disAddr ||) emitComp->opts.disAlignment))
else
{
for (unsigned cnt = ig->igInsCnt; cnt > 0; cnt--)
{
size_t curInstrAddr = (size_t)cp;
instrDesc* curInstrDesc = id;
#ifdef DEBUG
if ((emitComp->opts.disAsm || emitComp->verbose) && (JitConfig.JitDisasmWithDebugInfo() != 0) &&
(id->idCodeSize() > 0))
{
UNATIVE_OFFSET curCodeOffs = emitCurCodeOffs(cp);
while (nextMapping != emitComp->genRichIPmappings.end())
{
UNATIVE_OFFSET mappingOffs = nextMapping->nativeLoc.CodeOffset(this);

size_t afterInstrAddr = (size_t)cp;
instruction curIns = curInstrDesc->idIns();
bool isJccAffectedIns = false;

#if defined(TARGET_XARCH)
if (mappingOffs > curCodeOffs)
{
// Still haven't reached instruction that next mapping belongs to.
break;
}

// Determine if this instruction is part of a set that matches the Intel jcc erratum characteristic
// described here:
// https://www.intel.com/content/dam/support/us/en/documents/processors/mitigations-jump-conditional-code-erratum.pdf
// This is the case when a jump instruction crosses a 32-byte boundary, or ends on a 32-byte boundary.
// "Jump instruction" in this case includes conditional jump (jcc), macro-fused op-jcc (where 'op' is
// one of cmp, test, add, sub, and, inc, or dec), direct unconditional jump, indirect jump,
// direct/indirect call, and return.
// We reached the mapping or went past it.
if (mappingOffs == curCodeOffs)
{
emitDispInsIndent();
printf("; ");
nextMapping->debugInfo.Dump(true);
printf("\n");
}

size_t jccAlignBoundary = 32;
size_t jccAlignBoundaryMask = jccAlignBoundary - 1;
size_t jccLastBoundaryAddr = afterInstrAddr & ~jccAlignBoundaryMask;
++nextMapping;
}
}
#endif
size_t insSize = emitIssue1Instr(ig, id, &cp);
emitAdvanceInstrDesc(&id, insSize);

if (curInstrAddr < jccLastBoundaryAddr)
// Print the alignment boundary
if ((emitComp->opts.disAsm INDEBUG(|| emitComp->verbose)) &&
(INDEBUG(emitComp->opts.disAddr ||) emitComp->opts.disAlignment))
{
isJccAffectedIns = IsJccInstruction(curIns) || IsJmpInstruction(curIns) || (curIns == INS_call) ||
(curIns == INS_ret);
size_t afterInstrAddr = (size_t)cp;
instruction curIns = curInstrDesc->idIns();
bool isJccAffectedIns = false;

// For op-Jcc there are two cases: (1) curIns is the jcc, in which case the above condition
// already covers us. (2) curIns is the `op` and the next instruction is the `jcc`. Note that
// we will never have a `jcc` as the first instruction of a group, so we don't need to worry
// about looking ahead to the next group after a an `op` of `op-Jcc`.
#if defined(TARGET_XARCH)

if (!isJccAffectedIns && (cnt > 1))
// Determine if this instruction is part of a set that matches the Intel jcc erratum characteristic
// described here:
// https://www.intel.com/content/dam/support/us/en/documents/processors/mitigations-jump-conditional-code-erratum.pdf
// This is the case when a jump instruction crosses a 32-byte boundary, or ends on a 32-byte
// boundary.
// "Jump instruction" in this case includes conditional jump (jcc), macro-fused op-jcc (where 'op'
// is
// one of cmp, test, add, sub, and, inc, or dec), direct unconditional jump, indirect jump,
// direct/indirect call, and return.

size_t jccAlignBoundary = 32;
size_t jccAlignBoundaryMask = jccAlignBoundary - 1;
size_t jccLastBoundaryAddr = afterInstrAddr & ~jccAlignBoundaryMask;

if (curInstrAddr < jccLastBoundaryAddr)
{
// The current `id` is valid, namely, there is another instruction in this group.
instruction nextIns = id->idIns();
if (((curIns == INS_cmp) || (curIns == INS_test) || (curIns == INS_add) ||
(curIns == INS_sub) || (curIns == INS_and) || (curIns == INS_inc) ||
(curIns == INS_dec)) &&
IsJccInstruction(nextIns))
isJccAffectedIns = IsJccInstruction(curIns) || IsJmpInstruction(curIns) ||
(curIns == INS_call) || (curIns == INS_ret);

// For op-Jcc there are two cases: (1) curIns is the jcc, in which case the above condition
// already covers us. (2) curIns is the `op` and the next instruction is the `jcc`. Note that
// we will never have a `jcc` as the first instruction of a group, so we don't need to worry
// about looking ahead to the next group after a an `op` of `op-Jcc`.

if (!isJccAffectedIns && (cnt > 1))
{
isJccAffectedIns = true;
// The current `id` is valid, namely, there is another instruction in this group.
instruction nextIns = id->idIns();
if (((curIns == INS_cmp) || (curIns == INS_test) || (curIns == INS_add) ||
(curIns == INS_sub) || (curIns == INS_and) || (curIns == INS_inc) ||
(curIns == INS_dec)) &&
IsJccInstruction(nextIns))
{
isJccAffectedIns = true;
}
}
}

if (isJccAffectedIns)
{
unsigned bytesCrossedBoundary = (unsigned)(afterInstrAddr & jccAlignBoundaryMask);
printf("; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ (%s: %d ; jcc erratum) %dB boundary "
"...............................\n",
codeGen->genInsDisplayName(curInstrDesc), bytesCrossedBoundary, jccAlignBoundary);
if (isJccAffectedIns)
{
unsigned bytesCrossedBoundary = (unsigned)(afterInstrAddr & jccAlignBoundaryMask);
printf("; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ (%s: %d ; jcc erratum) %dB boundary "
"...............................\n",
codeGen->genInsDisplayName(curInstrDesc), bytesCrossedBoundary, jccAlignBoundary);
}
}
}

#elif defined(TARGET_LOONGARCH64)

isJccAffectedIns = true;
isJccAffectedIns = true;
#elif defined(TARGET_RISCV64)

isJccAffectedIns = true;
isJccAffectedIns = true;
#endif // TARGET_RISCV64

// Jcc affected instruction boundaries were printed above; handle other cases here.
if (!isJccAffectedIns)
{
size_t alignBoundaryMask = (size_t)emitComp->opts.compJitAlignLoopBoundary - 1;
size_t lastBoundaryAddr = afterInstrAddr & ~alignBoundaryMask;

// draw boundary if beforeAddr was before the lastBoundary.
if (curInstrAddr < lastBoundaryAddr)
// Jcc affected instruction boundaries were printed above; handle other cases here.
if (!isJccAffectedIns)
{
// Indicate if instruction is at the alignment boundary or is split
unsigned bytesCrossedBoundary = (unsigned)(afterInstrAddr & alignBoundaryMask);
if (bytesCrossedBoundary != 0)
{
printf("; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ (%s: %d)",
codeGen->genInsDisplayName(curInstrDesc), bytesCrossedBoundary);
}
else
size_t alignBoundaryMask = (size_t)emitComp->opts.compJitAlignLoopBoundary - 1;
size_t lastBoundaryAddr = afterInstrAddr & ~alignBoundaryMask;

// draw boundary if beforeAddr was before the lastBoundary.
if (curInstrAddr < lastBoundaryAddr)
{
printf("; ...............................");
// Indicate if instruction is at the alignment boundary or is split
unsigned bytesCrossedBoundary = (unsigned)(afterInstrAddr & alignBoundaryMask);
if (bytesCrossedBoundary != 0)
{
printf("; ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ (%s: %d)",
codeGen->genInsDisplayName(curInstrDesc), bytesCrossedBoundary);
}
else
{
printf("; ...............................");
}
printf(" %dB boundary ...............................\n",
emitComp->opts.compJitAlignLoopBoundary);
}
printf(" %dB boundary ...............................\n",
emitComp->opts.compJitAlignLoopBoundary);
}
}
}
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