Page MenuHomePhabricator
Differential D133863 Diff 463097 llvm/lib/Target/RISCV/RISCV.td

Changeset View

Standalone View

View Options

llvm/lib/Target/RISCV/RISCV.td

Show First 20 Lines • Show All 354 Lines • ▼ Show 20 Linesdef HasStdExtZca : Predicate<"Subtarget->hasStdExtZca()">,
"'Zca' (part of the C extension, excluding compressed floating point loads/stores)">; "'Zca' (part of the C extension, excluding compressed floating point loads/stores)">;
def HasStdExtCOrZca def HasStdExtCOrZca
: Predicate<"Subtarget->hasStdExtC() || Subtarget->hasStdExtZca()">, : Predicate<"Subtarget->hasStdExtC() || Subtarget->hasStdExtZca()">,
AssemblerPredicate<(any_of FeatureStdExtC, FeatureExtZca), AssemblerPredicate<(any_of FeatureStdExtC, FeatureExtZca),
"'C' (Compressed Instructions) or " "'C' (Compressed Instructions) or "
"'Zca' (part of the C extension, excluding compressed floating point loads/stores)">; "'Zca' (part of the C extension, excluding compressed floating point loads/stores)">;
def FeatureExtZcmt
: SubtargetFeature<"experimental-zcmt", "HasStdExtZcmt", "true",
"'Zcmt' (table jump instuctions for code-size reduction)",
[FeatureExtZca]>; // TODO: add Zicsr as another dependence
jrtc27Unsubmitted
Not Done
ReplyInline Actions

This is an odd implication, Zcmt works just fine without Zca?

jrtc27: This is an odd implication, Zcmt works just fine without Zca?
VincentWuAuthorUnsubmitted
Done
ReplyInline Actions

the spec says:

The Zcmt extension depends on the Zca and Zicsr extensions.

I think maybe zcmt needs to be aligned using c.nop? That might be one of the reasons why zcmt required zca.

VincentWu: the [[ https://github.com/riscv/riscv-code-size-reduction/releases/tag/v1.0.0-RC5.7 | spec ]]…
def HasStdExtZcmt : Predicate<"Subtarget->hasStdExtZcmt() && !Subtarget->hasStdExtC()">,
reamesUnsubmitted
Done
ReplyInline Actions

Wait, Zcmt can't be enabled if C is? That seems odd...

reames: Wait, Zcmt can't be enabled if C is? That seems odd...
craig.topperUnsubmitted
Done
ReplyInline Actions

I think Zcmt reuses encodings from the FP part of C. That's why C was split into Zca, Zcf, and Zcd.

craig.topper: I think Zcmt reuses encodings from the FP part of C. That's why C was split into Zca, Zcf, and…
jrtc27Unsubmitted
Done
ReplyInline Actions

Shouldn't the conflict be enforced at a higher level? Otherwise you're silently making +c,+zcmt resolve to +c here.

jrtc27: Shouldn't the conflict be enforced at a higher level? Otherwise you're silently making +c,+zcmt…
craig.topperUnsubmitted
Done
ReplyInline Actions

This restriction needs to be enforced in RISCVISAInfo.cpp so that it generates a proper error message.

craig.topper: This restriction needs to be enforced in RISCVISAInfo.cpp so that it generates a proper error…
AssemblerPredicate<(all_of FeatureExtZcmt, (not FeatureStdExtC)),
"'Zcmt' (table jump instuctions for code-size reduction)">;
def FeatureNoRVCHints def FeatureNoRVCHints
: SubtargetFeature<"no-rvc-hints", "EnableRVCHintInstrs", "false", : SubtargetFeature<"no-rvc-hints", "EnableRVCHintInstrs", "false",
"Disable RVC Hint Instructions.">; "Disable RVC Hint Instructions.">;
def HasRVCHints : Predicate<"Subtarget->enableRVCHintInstrs()">, def HasRVCHints : Predicate<"Subtarget->enableRVCHintInstrs()">,
AssemblerPredicate<(all_of(not FeatureNoRVCHints)), AssemblerPredicate<(all_of(not FeatureNoRVCHints)),
"RVC Hint Instructions">; "RVC Hint Instructions">;
def FeatureStdExtZvl32b : SubtargetFeature<"zvl32b", "ZvlLen", "32", def FeatureStdExtZvl32b : SubtargetFeature<"zvl32b", "ZvlLen", "32",
▲ Show 20 Lines • Show All 279 Lines • Show Last 20 Lines