[valgrind] [Bug 384676] VEX AMD64 backend should list more real registers as available for the register allocator
https://bugs.kde.org/show_bug.cgi?id=384676 Ivo Raisrchanged: What|Removed |Added Resolution|--- |WONTFIX Status|ASSIGNED|RESOLVED --- Comment #4 from Ivo Raisr --- Even after bug 384987 has been fixed, the situation did not improve much. Running Memcheck on perf/bz2 [number of instructions]: baseline: total: 44,936,961,809; reg alloc: 168,848,160; ratio: 15.3 patched: total: 44,933,693,157; reg alloc: 177,659,739; ratio: 15.3 Running Memcheck on perf/tinycc: baseline: total: 3,938,404,232; reg alloc: 121,447,931; ratio 16.2 patched: total: 3,939,903,162; reg alloc: 127,930,047; ratio 16.2 With perf/bz2, there is only a very minor improvement. With perf/tinycc there is actually a very minor deterioration. I am abandoning this bug for good. -- You are receiving this mail because: You are watching all bug changes.
[valgrind] [Bug 384676] VEX AMD64 backend should list more real registers as available for the register allocator
https://bugs.kde.org/show_bug.cgi?id=384676 Julian Sewardchanged: What|Removed |Added CC||jsew...@acm.org --- Comment #3 from Julian Seward --- Yes, that sounds pretty similar to what I found too. We maybe should re-evaluate this when the control-flow-diamond stuff comes to life, because it might be the case that that allows us to have longer sequences of instructions between helper calls and so there is more demand for registers. -- You are receiving this mail because: You are watching all bug changes.
[valgrind] [Bug 384676] VEX AMD64 backend should list more real registers as available for the register allocator
https://bugs.kde.org/show_bug.cgi?id=384676 --- Comment #2 from Ivo Raisr--- Unfortunately performance measurements do not confirm this as a good idea. Measuring Memcheck on perf/bz2, instruction count: v3 baseline: 45,110 M total; 168 M register allocator v3 patched: 45,123 M total; 176 M register allocator v2 baseline: 45,190 M total; 209 M register allocator v2 patched: 45,266 M total; 220 M register allocator Measuring Memcheck on tinycc, instruction count: v3 baseline: 4,155,471 k total; 86,438 k register allocator v3 patched: 4,155,207 k total; 91,193 k register allocator I'd conclude that although two more registers are available to the register allocator, it does not help because: - they are caller saved registers - register allocator needs to iterate over more registers -- You are receiving this mail because: You are watching all bug changes.
[valgrind] [Bug 384676] VEX AMD64 backend should list more real registers as available for the register allocator
https://bugs.kde.org/show_bug.cgi?id=384676 Ivo Raisrchanged: What|Removed |Added See Also||https://bugs.kde.org/show_b ||ug.cgi?id=384584 -- You are receiving this mail because: You are watching all bug changes.
[valgrind] [Bug 384676] VEX AMD64 backend should list more real registers as available for the register allocator
https://bugs.kde.org/show_bug.cgi?id=384676 Ivo Raisrchanged: What|Removed |Added CC||iv...@ivosh.net --- Comment #1 from Ivo Raisr --- Created attachment 107840 --> https://bugs.kde.org/attachment.cgi?id=107840=edit patch -- You are receiving this mail because: You are watching all bug changes.
[valgrind] [Bug 384676] VEX AMD64 backend should list more real registers as available for the register allocator
https://bugs.kde.org/show_bug.cgi?id=384676 Ivo Raisrchanged: What|Removed |Added Ever confirmed|0 |1 Assignee|jsew...@acm.org |iv...@ivosh.net Status|UNCONFIRMED |ASSIGNED -- You are receiving this mail because: You are watching all bug changes.