auto merge of #16710 : dotdash/rust/mergefunc, r=thestinger

bors · bors · commit 471862f40cbb · 2014-08-24T09:30:56.000Z
Fixes #9536 --- From #9536 (comment): I've built rustc with the aforementioned fix, once with MergeFunc being run early (that's what the patch for clang that comes with LLVM does), and once with MergeFunc being run late (using `-C passes=mergefunc`). Here are some time/code size measurements I made with them: Build command: `rustc -O -o /dev/null --emit asm .../lib.rs` CPU (user) times, best of three runs: Crate | No MergeFunc | Early MergeFunc | Late MergeFunc -------------|--------------|-----------------|--------------- core | 5.380s | 5.476s | 5.364s collections | 1.884s | 1.856s | 1.892s native | 7.200s | 7.356s | 7.108s rustc | 3m23.584s | 3m28.120s | 3m21.820s std | 13.888s | 13.976s | 13.848s syntax | 48.992s | 47.752s | 48.372s Sizes: Crate | No MergeFunc | Early MergeFunc | Late MergeFunc -----------------------------------------|-------------:|--------------------:|-------------------: lib | 237037581 | 236005998 (-0.44%) | 234708744 (-0.98%) libarena-063bff73-0.11.0-pre.so | 60398 | 60393 (-0.01%) | 60394 (-0.01%) libcollections-d412c0c4-0.11.0-pre.so | 971566 | 971772 (+0.02%) | 971691 (+0.01%) libdebug-1e940314-0.11.0-pre.so | 181352 | 181514 (+0.09%) | 181363 (+0.01%) libflate-92afea7e-0.11.0-pre.so | 137837 | 137869 (+0.02%) | 137837 (+0.00%) libfmt_macros-5125f3bd-0.11.0-pre.so | 132733 | 134598 (+1.41%) | 132465 (-0.20%) libgetopts-c94737d1-0.11.0-pre.so | 158851 | 157427 (-0.90%) | 158272 (-0.36%) libgraphviz-7b3cf89d-0.11.0-pre.so | 53337 | 53178 (-0.30%) | 53337 (+0.00%) liblog-cd053230-0.11.0-pre.so | 85993 | 86017 (+0.03%) | 85780 (-0.25%) libnative-1fb5e2c0-0.11.0-pre.so | 635785 | 639352 (+0.56%) | 621184 (-2.30%) libregex-77385931-0.11.0-pre.so | 450538 | 450741 (+0.05%) | 449504 (-0.23%) librustc-d252d482-0.11.0-pre.so | 51583741 | 5122770 (-0.69%) | 50930784 (-1.27%) librustdoc-6ecbf63e-0.11.0-pre.so | 4557104 | 4501896 (-1.21%) | 4394409 (-3.57%) libserialize-0352aab7-0.11.0-pre.so | 1126096 | 1115503 (-0.94%) | 1101734 (-2.16%) libstd-59beb4f7-0.11.0-pre.so | 4499529 | 4488879 (-0.24%) | 4477710 (-0.48%) libsync-305341d2-0.11.0-pre.so | 306767 | 312211 (+1.77%) | 304086 (-0.87%) libsyntax-555559ea-0.11.0-pre.so | 6699751 | 6632291 (-1.01%) | 6596232 (-1.55%) libterm-4e4945a5-0.11.0-pre.so | 389390 | 392689 (+0.85%) | 385525 (-0.99%) libtest-a79f950d-0.11.0-pre.so | 740161 | 730673 (-1.28%) | 734534 (-0.76%) libtime-4bb3739b-0.11.0-pre.so | 131518 | 132830 (+1.00%) | 131514 (-0.00%) rustlib | 164131038 | 163594366 (-0.33%) | 162796293 (-0.81%) x86_64-unknown-linux-gnu | 164119867 | 163583195 (-0.33%) | 162785122 (-0.81%) lib | 164115771 | 163579099 (-0.33%) | 162781026 (-0.81%) liballoc-1085c790-0.11.0-pre.rlib | 1094410 | 1094444 (+0.00%) | 1094438 (+0.00%) libarena-063bff73-0.11.0-pre.rlib | 312324 | 312152 (-0.06%) | 312210 (-0.04%) libarena-063bff73-0.11.0-pre.so | 60394 | 60394 (+0.00%) | 60394 (+0.00%) libcollections-d412c0c4-0.11.0-pre.rlib | 7048646 | 7049094 (+0.01%) | 7048856 (+0.00%) libcollections-d412c0c4-0.11.0-pre.so | 971575 | 971771 (+0.02%) | 971681 (+0.01%) libcompiler-rt.a | 573802 | 573802 (+0.00%) | 573802 (+0.00%) libcore-c5ed6fb4-0.11.0-pre.rlib | 24204746 | 24209820 (+0.02%) | 24187602 (-0.07%) libdebug-1e940314-0.11.0-pre.rlib | 876616 | 878488 (+0.21%) | 876746 (+0.01%) libdebug-1e940314-0.11.0-pre.so | 181352 | 181509 (+0.09%) | 181353 (+0.00%) libflate-92afea7e-0.11.0-pre.rlib | 175062 | 175074 (+0.01%) | 175082 (+0.01%) libflate-92afea7e-0.11.0-pre.so | 137837 | 137869 (+0.02%) | 137837 (+0.00%) libfmt_macros-5125f3bd-0.11.0-pre.so | 132724 | 134599 (+1.41%) | 132469 (-0.19%) libfourcc-cc0e8bf1-0.11.0-pre.so | 125828 | 126084 (+0.20%) | 125827 (-0.00%) libgetopts-c94737d1-0.11.0-pre.rlib | 864664 | 853040 (-1.34%) | 862548 (-0.24%) libgetopts-c94737d1-0.11.0-pre.so | 158855 | 157425 (-0.90%) | 158275 (-0.37%) libglob-eafe1d22-0.11.0-pre.rlib | 951370 | 944674 (-0.70%) | 946734 (-0.49%) libglob-eafe1d22-0.11.0-pre.so | 159130 | 157385 (-1.10%) | 156791 (-1.47%) libgraphviz-7b3cf89d-0.11.0-pre.rlib | 269600 | 269062 (-0.20%) | 269560 (-0.01%) libgraphviz-7b3cf89d-0.11.0-pre.so | 53334 | 53176 (-0.30%) | 53337 (+0.01%) libgreen-ca0d0b80-0.11.0-pre.rlib | 1374120 | 1389510 (+1.12%) | 1361696 (-0.90%) libgreen-ca0d0b80-0.11.0-pre.so | 372435 | 377929 (+1.48%) | 370991 (-0.39%) libhexfloat-3b978f48-0.11.0-pre.so | 131926 | 132166 (+0.18%) | 131935 (+0.01%) liblibc-4f9a876d-0.11.0-pre.rlib | 617472 | 617472 (+0.00%) | 617472 (+0.00%) liblog-cd053230-0.11.0-pre.rlib | 371190 | 371048 (-0.04%) | 370836 (-0.10%) liblog-cd053230-0.11.0-pre.so | 85996 | 86020 (+0.03%) | 85781 (-0.25%) libmorestack.a | 1388 | 1388 (+0.00%) | 1388 (+0.00%) libnative-1fb5e2c0-0.11.0-pre.rlib | 2233070 | 2264296 (+1.40%) | 2194920 (-1.71%) libnative-1fb5e2c0-0.11.0-pre.so | 635787 | 639341 (+0.56%) | 621184 (-2.30%) libnum-ebe12db7-0.11.0-pre.rlib | 2672318 | 2675292 (+0.11%) | 2669370 (-0.11%) libnum-ebe12db7-0.11.0-pre.so | 398924 | 399357 (+0.11%) | 395821 (-0.78%) librand-2ea8f361-0.11.0-pre.rlib | 1691108 | 1691696 (+0.03%) | 1690264 (-0.05%) libregex-77385931-0.11.0-pre.rlib | 2007348 | 2006050 (-0.06%) | 2003804 (-0.18%) libregex-77385931-0.11.0-pre.so | 450520 | 450790 (+0.06%) | 449535 (-0.22%) libregex_macros-a2216dec-0.11.0-pre.so | 597208 | 569004 (-4.72%) | 568800 (-4.76%) librlibc-d1ece24e-0.11.0-pre.rlib | 12394 | 12394 (+0.00%) | 12394 (+0.00%) librustc-d252d482-0.11.0-pre.so | 51582383 | 51230320 (-0.68%) | 50930784 (-1.26%) librustdoc-6ecbf63e-0.11.0-pre.so | 4557074 | 4501877 (-1.21%) | 4394506 (-3.57%) librustuv-ede8cb89-0.11.0-pre.rlib | 4774956 | 4791366 (+0.34%) | 4732386 (-0.89%) librustuv-ede8cb89-0.11.0-pre.so | 1401710 | 1400237 (-0.11%) | 1386869 (-1.06%) libsemver-e49a2dee-0.11.0-pre.rlib | 392704 | 392434 (-0.07%) | 392940 (+0.06%) libsemver-e49a2dee-0.11.0-pre.so | 71863 | 71847 (-0.02%) | 71860 (-0.00%) libserialize-0352aab7-0.11.0-pre.rlib | 8059698 | 8033972 (-0.32%) | 7989802 (-0.87%) libserialize-0352aab7-0.11.0-pre.so | 1126099 | 1115520 (-0.94%) | 1101721 (-2.16%) libstd-59beb4f7-0.11.0-pre.rlib | 18802728 | 18780212 (-0.12%) | 18743438 (-0.32%) libstd-59beb4f7-0.11.0-pre.so | 4499534 | 4488835 (-0.24%) | 4477677 (-0.49%) libsync-305341d2-0.11.0-pre.rlib | 1377062 | 1400190 (+1.68%) | 1369498 (-0.55%) libsync-305341d2-0.11.0-pre.so | 306762 | 312212 (+1.78%) | 304095 (-0.87%) libsyntax-555559ea-0.11.0-pre.so | 6703330 | 6632254 (-1.06%) | 6596295 (-1.60%) libterm-4e4945a5-0.11.0-pre.rlib | 1503928 | 1512648 (+0.58%) | 1495932 (-0.53%) libterm-4e4945a5-0.11.0-pre.so | 389380 | 392678 (+0.85%) | 385517 (-0.99%) libtest-a79f950d-0.11.0-pre.rlib | 3606962 | 3555410 (-1.43%) | 3589258 (-0.49%) libtest-a79f950d-0.11.0-pre.so | 740255 | 728398 (-1.60%) | 734521 (-0.77%) libtime-4bb3739b-0.11.0-pre.rlib | 847036 | 847178 (+0.02%) | 847194 (+0.02%) libtime-4bb3739b-0.11.0-pre.so | 131516 | 132829 (+1.00%) | 131518 (+0.00%) liburl-b8b5640c-0.11.0-pre.rlib | 647764 | 647558 (-0.03%) | 646896 (-0.13%) liburl-b8b5640c-0.11.0-pre.so | 146616 | 146621 (+0.00%) | 146531 (-0.06%) libuuid-238d8f44-0.11.0-pre.rlib | 359732 | 359682 (-0.01%) | 358936 (-0.22%) libuuid-238d8f44-0.11.0-pre.so | 77110 | 77110 (+0.00%) | 77023 (-0.11%) total | 237081476 | 236049893 (-0.44%) | 234752639 (-0.98%) So running MergeFunc early like in the clang patch isn't nearly as good as running it late. I also tried to enable usage of global aliases instead of just thunks when merging functions, but that crashes.
diff --git a/src/librustc/back/link.rs b/src/librustc/back/link.rs
@@ -536,6 +536,13 @@ pub mod write {
         llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(builder, fpm);
         llvm::LLVMPassManagerBuilderPopulateModulePassManager(builder, mpm);
         llvm::LLVMPassManagerBuilderDispose(builder);
+
+        match opt {
+            llvm::CodeGenLevelDefault | llvm::CodeGenLevelAggressive => {
+                "mergefunc".with_c_str(|s| llvm::LLVMRustAddPass(mpm, s));
+            }
+            _ => {}
+        };
     }
 }
 

Original file line number	Diff line number	Diff line change
`@@ -536,6 +536,13 @@ pub mod write {`
`536`	`536`	`llvm::LLVMPassManagerBuilderPopulateFunctionPassManager(builder, fpm);`
`537`	`537`	`llvm::LLVMPassManagerBuilderPopulateModulePassManager(builder, mpm);`
`538`	`538`	`llvm::LLVMPassManagerBuilderDispose(builder);`
	`539`	`+`
	`540`	`+ match opt {`
	`541`	`+ llvm::CodeGenLevelDefault \| llvm::CodeGenLevelAggressive => {`
	`542`	`+ "mergefunc".with_c_str(\|s\| llvm::LLVMRustAddPass(mpm, s));`
	`543`	`+ }`
	`544`	`+ _ => {}`
	`545`	`+ };`
`539`	`546`	`}`
`540`	`547`	`}`
`541`	`548`