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4845f40dff
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>
80 lines
2.7 KiB
C++
80 lines
2.7 KiB
C++
// Part of the Carbon Language project, under the Apache License v2.0 with LLVM
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// Exceptions. See /LICENSE for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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#include "toolchain/check/context.h"
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#include "toolchain/check/convert.h"
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#include "toolchain/check/handle.h"
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namespace Carbon::Check {
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auto HandleParseNode(Context& /*context*/,
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Parse::IfConditionStartId /*node_id*/) -> bool {
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return true;
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}
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auto HandleParseNode(Context& context, Parse::IfConditionId node_id) -> bool {
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// Convert the condition to `bool`.
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auto cond_value_id = context.node_stack().PopExpr();
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cond_value_id = ConvertToBoolValue(context, node_id, cond_value_id);
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// Create the then block and the else block, and branch to the right one. If
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// there is no `else`, the then block will terminate with a branch to the
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// else block, which will be reused as the resumption block.
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auto then_block_id =
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context.AddDominatedBlockAndBranchIf(node_id, cond_value_id);
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auto else_block_id = context.AddDominatedBlockAndBranch(node_id);
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// Start emitting the `then` block.
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context.inst_block_stack().Pop();
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context.inst_block_stack().Push(then_block_id);
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context.AddCurrentCodeBlockToFunction();
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context.node_stack().Push(node_id, else_block_id);
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return true;
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}
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auto HandleParseNode(Context& context, Parse::IfStatementElseId node_id)
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-> bool {
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auto else_block_id = context.node_stack().Pop<Parse::NodeKind::IfCondition>();
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// Switch to emitting the `else` block.
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context.inst_block_stack().Push(else_block_id);
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context.AddCurrentCodeBlockToFunction();
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context.node_stack().Push(node_id);
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return true;
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}
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auto HandleParseNode(Context& context, Parse::IfStatementId node_id) -> bool {
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switch (auto kind = context.node_stack().PeekNodeKind()) {
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case Parse::NodeKind::IfCondition: {
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// Branch from then block to else block, and start emitting the else
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// block.
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auto else_block_id =
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context.node_stack().Pop<Parse::NodeKind::IfCondition>();
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context.AddInst<SemIR::Branch>(node_id, {.target_id = else_block_id});
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context.inst_block_stack().Pop();
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context.inst_block_stack().Push(else_block_id);
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break;
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}
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case Parse::NodeKind::IfStatementElse: {
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// Branch from the then and else blocks to a new resumption block.
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context.node_stack()
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.PopAndDiscardSoloNodeId<Parse::NodeKind::IfStatementElse>();
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context.AddConvergenceBlockAndPush(node_id, /*num_blocks=*/2);
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break;
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}
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default: {
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CARBON_FATAL("Unexpected parse node at start of `if`: {0}", kind);
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}
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}
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context.AddCurrentCodeBlockToFunction();
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return true;
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}
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} // namespace Carbon::Check
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