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path: root/src/cmd/compile/internal/ssa/biasedsparsemap.go
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2019-05-14cmd/compile: index line number tables by source file to improve sparsityDavid Chase
This reduces allocations and also resolves some lurking inliner/inlinee line-number match problems. However, it does add about 1.5% to compile time. This fixes compiler OOMs seen compiling some large protobuf- derived inputs. For compiling the compiler itself, compilebench -pkg cmd/compile/internal/ssa -memprofile withcl.prof the numberlines-related memory consumption is reduced from 129MB to 29MB (about a 5% overall reduction in allocation). Additionally modified after going over changes with Austin to remove unused code (nobody called size()) and correct the cache-clearing code. I've attempted to speed this up by not using maps, and have not succeeded. I'd rather get correct code in now, speed it up later if I can. Updates #27739. Fixes #29279. Change-Id: I098005de4e45196a5f5b10c0886a49f88e9f8fd5 Reviewed-on: https://go-review.googlesource.com/c/go/+/154617 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org>
2018-12-02all: use "reports whether" consistently instead of "returns whether"Tobias Klauser
Follow-up for CL 147037 and after Brad noticed the "returns whether" pattern during the review of CL 150621. Go documentation style for boolean funcs is to say: // Foo reports whether ... func Foo() bool (rather than "returns whether") Created with: $ perl -i -npe 's/returns whether/reports whether/' $(git grep -l "returns whether" | grep -v vendor) Change-Id: I15fe9ff99180ad97750cd05a10eceafdb12dc0b4 Reviewed-on: https://go-review.googlesource.com/c/150918 Run-TryBot: Tobias Klauser <tobias.klauser@gmail.com> Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>
2018-05-14cmd/compile: assign and preserve statement boundaries.David Chase
A new pass run after ssa building (before any other optimization) identifies the "first" ssa node for each statement. Other "noise" nodes are tagged as being never appropriate for a statement boundary (e.g., VarKill, VarDef, Phi). Rewrite, deadcode, cse, and nilcheck are modified to move the statement boundaries forward whenever possible if a boundary-tagged ssa value is removed; never-boundary nodes are ignored in this search (some operations involving constants are also tagged as never-boundary and also ignored because they are likely to be moved or removed during optimization). Code generation treats all nodes except those explicitly marked as statement boundaries as "not statement" nodes, and floats statement boundaries to the beginning of each same-line run of instructions found within a basic block. Line number html conversion was modified to make statement boundary nodes a bit more obvious by prepending a "+". The code in fuse.go that glued together the value slices of two blocks produced a result that depended on the former capacities (not lengths) of the two slices. This causes differences in the 386 bootstrap, and also can sometimes put values into an order that does a worse job of preserving statement boundaries when values are removed. Portions of two delve tests that had caught problems were incorporated into ssa/debug_test.go. There are some opportunities to do better with optimized code, but the next-ing is not lying or overly jumpy. Over 4 CLs, compilebench geomean measured binary size increase of 3.5% and compile user time increase of 3.8% (this is after optimization to reuse a sparse map instead of creating multiple maps.) This CL worsens the optimized-debugging experience with Delve; we need to work with the delve team so that they can use the is_stmt marks that we're emitting now. The reference output changes from time to time depending on other changes in the compiler, sometimes better, sometimes worse. This CL now includes a test ensuring that 99+% of the lines in the Go command itself (a handy optimized binary) include is_stmt markers. Change-Id: I359c94e06843f1eb41f9da437bd614885aa9644a Reviewed-on: https://go-review.googlesource.com/102435 Run-TryBot: David Chase <drchase@google.com> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Austin Clements <austin@google.com>