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[turbofan] Add method to extend smis to effect control linearizer

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We were abusing of ChangeInt32ToIntPtr since we were using it with Smis
as inputs. The new ChangeTaggedInt32ToSmi takes a smi value in 32 bits
and extends it (if necessary) to 64 bits.

Knowing it's a smi lets us skip the ChangeInt32ToInt64 when we are
using 31 bit smis.

Change-Id: Ibd88127fa8122d4b9f683151469cd37320515b5c
Reviewed-on: https://chromium-review.googlesource.com/c/v8/v8/+/1921985
Commit-Queue: Santiago Aboy Solanes <solanes@chromium.org>
Reviewed-by: Jakob Gruber <jgruber@chromium.org>
Reviewed-by: Tobias Tebbi <tebbi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#65180}
This commit is contained in:
Santiago Aboy Solanes 2019-11-26 15:34:15 +00:00 committed by Commit Bot
parent 3885b79e21
commit 3252ee85f3
1 changed files with 22 additions and 10 deletions
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32
src/compiler/effect-control-linearizer.cc
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@ -231,6 +231,12 @@ class EffectControlLinearizer {
Node* BuildTypedArrayDataPointer(Node* base, Node* external); Node* BuildTypedArrayDataPointer(Node* base, Node* external);
Node* ChangeInt32ToSmi(Node* value); Node* ChangeInt32ToSmi(Node* value);
// In pointer compression, we smi-corrupt. This means the upper bits of a Smi
// are not important. ChangeTaggedInt32ToSmi has a known tagged int32 as input
// and takes advantage of the smi corruption by emitting a Bitcast node
// instead of a Change node in order to save instructions.
// In non pointer compression, it behaves like ChangeInt32ToSmi.
Node* ChangeTaggedInt32ToSmi(Node* value);
Node* ChangeInt32ToIntPtr(Node* value); Node* ChangeInt32ToIntPtr(Node* value);
Node* ChangeInt64ToSmi(Node* value); Node* ChangeInt64ToSmi(Node* value);
Node* ChangeIntPtrToInt32(Node* value); Node* ChangeIntPtrToInt32(Node* value);
@ -1349,7 +1355,7 @@ Node* EffectControlLinearizer::LowerChangeFloat64ToTagged(Node* node) {
Node* ovf = __ Projection(1, add); Node* ovf = __ Projection(1, add);
__ GotoIf(ovf, &if_heapnumber); __ GotoIf(ovf, &if_heapnumber);
Node* value_smi = __ Projection(0, add); Node* value_smi = __ Projection(0, add);
value_smi = ChangeInt32ToIntPtr(value_smi); value_smi = ChangeTaggedInt32ToSmi(value_smi);
__ Goto(&done, value_smi); __ Goto(&done, value_smi);
} }
} }
@ -1405,7 +1411,7 @@ Node* EffectControlLinearizer::LowerChangeInt32ToTagged(Node* node) {
Node* ovf = __ Projection(1, add); Node* ovf = __ Projection(1, add);
__ GotoIf(ovf, &if_overflow); __ GotoIf(ovf, &if_overflow);
Node* value_smi = __ Projection(0, add); Node* value_smi = __ Projection(0, add);
value_smi = ChangeInt32ToIntPtr(value_smi); value_smi = ChangeTaggedInt32ToSmi(value_smi);
__ Goto(&done, value_smi); __ Goto(&done, value_smi);
__ Bind(&if_overflow); __ Bind(&if_overflow);
@ -1433,7 +1439,7 @@ Node* EffectControlLinearizer::LowerChangeInt64ToTagged(Node* node) {
Node* add = __ Int32AddWithOverflow(value32, value32); Node* add = __ Int32AddWithOverflow(value32, value32);
Node* ovf = __ Projection(1, add); Node* ovf = __ Projection(1, add);
__ GotoIf(ovf, &if_not_in_smi_range); __ GotoIf(ovf, &if_not_in_smi_range);
Node* value_smi = ChangeInt32ToIntPtr(__ Projection(0, add)); Node* value_smi = ChangeTaggedInt32ToSmi(__ Projection(0, add));
__ Goto(&done, value_smi); __ Goto(&done, value_smi);
} }
@ -2271,12 +2277,14 @@ Node* EffectControlLinearizer::LowerCheckedInt32ToTaggedSigned(
Node* value = node->InputAt(0); Node* value = node->InputAt(0);
const CheckParameters& params = CheckParametersOf(node->op()); const CheckParameters& params = CheckParametersOf(node->op());
// Check for the lost precision at the same time that we are smi tagging.
Node* add = __ Int32AddWithOverflow(value, value); Node* add = __ Int32AddWithOverflow(value, value);
Node* check = __ Projection(1, add); Node* check = __ Projection(1, add);
__ DeoptimizeIf(DeoptimizeReason::kLostPrecision, params.feedback(), check, __ DeoptimizeIf(DeoptimizeReason::kLostPrecision, params.feedback(), check,
frame_state); frame_state);
// Since smi tagging shifts left by one, it's the same as adding value twice.
Node* result = __ Projection(0, add); Node* result = __ Projection(0, add);
result = ChangeInt32ToIntPtr(result); result = ChangeTaggedInt32ToSmi(result);
return result; return result;
} }
@ -2310,7 +2318,7 @@ Node* EffectControlLinearizer::LowerCheckedInt64ToTaggedSigned(
__ DeoptimizeIf(DeoptimizeReason::kLostPrecision, params.feedback(), check, __ DeoptimizeIf(DeoptimizeReason::kLostPrecision, params.feedback(), check,
frame_state); frame_state);
Node* result = __ Projection(0, add); Node* result = __ Projection(0, add);
result = ChangeInt32ToIntPtr(result); result = ChangeTaggedInt32ToSmi(result);
return result; return result;
} }
} }
@ -4425,15 +4433,19 @@ Node* EffectControlLinearizer::AllocateHeapNumberWithValue(Node* value) {
Node* EffectControlLinearizer::ChangeIntPtrToSmi(Node* value) { Node* EffectControlLinearizer::ChangeIntPtrToSmi(Node* value) {
// Do shift on 32bit values if Smis are stored in the lower word. // Do shift on 32bit values if Smis are stored in the lower word.
if (machine()->Is64() && SmiValuesAre31Bits()) { if (machine()->Is64() && SmiValuesAre31Bits()) {
Node* smi_value = __ Word32Shl(value, SmiShiftBitsConstant()); return ChangeTaggedInt32ToSmi(__ Word32Shl(value, SmiShiftBitsConstant()));
// In pointer compression, we smi-corrupt. Then, the upper bits are not
// important.
return COMPRESS_POINTERS_BOOL ? __ BitcastWord32ToWord64(smi_value)
: __ ChangeInt32ToInt64(smi_value);
} }
return __ WordShl(value, SmiShiftBitsConstant()); return __ WordShl(value, SmiShiftBitsConstant());
} }
Node* EffectControlLinearizer::ChangeTaggedInt32ToSmi(Node* value) {
DCHECK(SmiValuesAre31Bits());
// In pointer compression, we smi-corrupt. Then, the upper bits are not
// important.
return COMPRESS_POINTERS_BOOL ? __ BitcastWord32ToWord64(value)
: ChangeInt32ToIntPtr(value);
}
Node* EffectControlLinearizer::ChangeInt32ToIntPtr(Node* value) { Node* EffectControlLinearizer::ChangeInt32ToIntPtr(Node* value) {
if (machine()->Is64()) { if (machine()->Is64()) {
value = __ ChangeInt32ToInt64(value); value = __ ChangeInt32ToInt64(value);