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Switch CARBON_CHECK to a format string API (#4285)
This switches `DCHECK` and `FATAL` as well. The goal is to reduce the code size impact of these assertions so that we can keep more of them enabled. Currently, the largest cost I see from `CHECK` is not the actual check or the cold code itself, but actually the failure to inline trivial functions due to the presence of the cold code. This means that our goal isn't to reduce apparent code size in the final binary but the LLVM IR cost assessed for these routines in the inliner, which closely correlates with code size but is a bit different. As discussed in #4283, experimentation shows that a single function call with a minimal number of arguments is the lowest cost model for these. This is easily achieved with a format-string API that internally uses `llvm::formatv`. This PR is essentially the `CHECK` version of #4283. However, the check macros are substantially harder to make work with both format strings and streaming because they also take a condition. Also, unexpectedly, I was very successful at devising a regular expression based automated rewrite from the streaming to the format string form with only low 10s of manual fixes. This includes compacting strings broken up across lines, etc. Given how well that went, I've prepared this PR which just directly switches to the format string API and migrate everything to use it. One nice side-effect is that the format string approach ends up greatly simplifying the implementation here as well. This is ... *shockingly* effective. Parsing speeds up by more than 3% with just this change. And checking speeds up by **8%** with this change alone: ``` BM_CompileAPIFileDenseDecls<Phase::Parse>/256 86.3µs ± 1% 82.9µs ± 1% -3.94% (p=0.000 n=17+19) BM_CompileAPIFileDenseDecls<Phase::Parse>/1024 431µs ± 1% 415µs ± 1% -3.76% (p=0.000 n=18+19) BM_CompileAPIFileDenseDecls<Phase::Parse>/4096 1.77ms ± 1% 1.71ms ± 1% -3.18% (p=0.000 n=18+19) BM_CompileAPIFileDenseDecls<Phase::Parse>/16384 7.44ms ± 1% 7.17ms ± 2% -3.56% (p=0.000 n=18+20) BM_CompileAPIFileDenseDecls<Phase::Parse>/65536 30.7ms ± 1% 29.7ms ± 1% -3.15% (p=0.000 n=18+20) BM_CompileAPIFileDenseDecls<Phase::Parse>/262144 131ms ± 1% 127ms ± 1% -2.81% (p=0.000 n=18+18) BM_CompileAPIFileDenseDecls<Phase::Check>/256 878µs ± 2% 800µs ± 1% -8.91% (p=0.000 n=19+20) BM_CompileAPIFileDenseDecls<Phase::Check>/1024 1.88ms ± 2% 1.72ms ± 1% -8.56% (p=0.000 n=19+20) BM_CompileAPIFileDenseDecls<Phase::Check>/4096 5.78ms ± 2% 5.28ms ± 1% -8.70% (p=0.000 n=20+18) BM_CompileAPIFileDenseDecls<Phase::Check>/16384 21.9ms ± 1% 20.1ms ± 1% -8.02% (p=0.000 n=18+20) BM_CompileAPIFileDenseDecls<Phase::Check>/65536 90.4ms ± 2% 83.1ms ± 1% -8.04% (p=0.000 n=19+20) BM_CompileAPIFileDenseDecls<Phase::Check>/262144 381ms ± 2% 352ms ± 1% -7.79% (p=0.000 n=19+19) ``` --------- Co-authored-by: Richard Smith <richard@metafoo.co.uk> Co-authored-by: josh11b <15258583+josh11b@users.noreply.github.com>
This commit is contained in:
Chandler Carruth
co-authored by
Richard Smith
josh11b
Richard Smith
josh11b
parent
35dfa5f03c
commit
4845f40dff
@@ -34,16 +34,16 @@ static auto GetAggregateElement(FunctionContext& context,
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case SemIR::ExprCategory::NotExpr:
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case SemIR::ExprCategory::Initializing:
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case SemIR::ExprCategory::Mixed:
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CARBON_FATAL() << "Unexpected expression category for aggregate access";
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CARBON_FATAL("Unexpected expression category for aggregate access");
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case SemIR::ExprCategory::Value: {
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auto value_rep =
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SemIR::ValueRepr::ForType(context.sem_ir(), aggr_inst.type_id());
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CARBON_CHECK(value_rep.aggregate_kind != SemIR::ValueRepr::NotAggregate)
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<< "aggregate type should have aggregate value representation";
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CARBON_CHECK(value_rep.aggregate_kind != SemIR::ValueRepr::NotAggregate,
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"aggregate type should have aggregate value representation");
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switch (value_rep.kind) {
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case SemIR::ValueRepr::Unknown:
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CARBON_FATAL() << "Lowering access to incomplete aggregate type";
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CARBON_FATAL("Lowering access to incomplete aggregate type");
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case SemIR::ValueRepr::None:
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return aggr_value;
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case SemIR::ValueRepr::Copy:
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@@ -73,8 +73,8 @@ static auto GetAggregateElement(FunctionContext& context,
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context.GetType(result_value_type_id), elem_ptr, name + ".load");
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}
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case SemIR::ValueRepr::Custom:
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CARBON_FATAL()
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<< "Aggregate should never have custom value representation";
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CARBON_FATAL(
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"Aggregate should never have custom value representation");
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}
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}
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@@ -132,8 +132,9 @@ static auto EmitAggregateInitializer(FunctionContext& context,
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case SemIR::InitRepr::ByCopy: {
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auto refs = context.sem_ir().inst_blocks().Get(refs_id);
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CARBON_CHECK(refs.size() == 1)
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<< "Unexpected size for aggregate with by-copy value representation";
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CARBON_CHECK(
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refs.size() == 1,
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"Unexpected size for aggregate with by-copy value representation");
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// TODO: Remove the LLVM StructType wrapper in this case, so we don't
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// need this `insert_value` wrapping.
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return context.builder().CreateInsertValue(
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@@ -142,8 +143,8 @@ static auto EmitAggregateInitializer(FunctionContext& context,
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}
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case SemIR::InitRepr::Incomplete:
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CARBON_FATAL() << "Lowering aggregate initialization of incomplete type "
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<< context.sem_ir().types().GetAsInst(type_id);
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CARBON_FATAL("Lowering aggregate initialization of incomplete type {0}",
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context.sem_ir().types().GetAsInst(type_id));
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}
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}
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@@ -177,7 +178,7 @@ static auto EmitAggregateValueRepr(FunctionContext& context,
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auto value_rep = SemIR::ValueRepr::ForType(context.sem_ir(), type_id);
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switch (value_rep.kind) {
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case SemIR::ValueRepr::Unknown:
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CARBON_FATAL() << "Incomplete aggregate type in lowering";
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CARBON_FATAL("Incomplete aggregate type in lowering");
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case SemIR::ValueRepr::None:
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// TODO: Add a helper to get a "no value representation" value.
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@@ -185,8 +186,9 @@ static auto EmitAggregateValueRepr(FunctionContext& context,
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case SemIR::ValueRepr::Copy: {
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auto refs = context.sem_ir().inst_blocks().Get(refs_id);
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CARBON_CHECK(refs.size() == 1)
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<< "Unexpected size for aggregate with by-copy value representation";
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CARBON_CHECK(
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refs.size() == 1,
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"Unexpected size for aggregate with by-copy value representation");
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// TODO: Remove the LLVM StructType wrapper in this case, so we don't
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// need this `insert_value` wrapping.
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return context.builder().CreateInsertValue(
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@@ -211,8 +213,7 @@ static auto EmitAggregateValueRepr(FunctionContext& context,
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}
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case SemIR::ValueRepr::Custom:
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CARBON_FATAL()
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<< "Aggregate should never have custom value representation";
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CARBON_FATAL("Aggregate should never have custom value representation");
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}
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}
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