Keith Randall fb05948d9e cmd/compile,math: improve code generation for math.Abs ... Implement int reg <-> fp reg moves on amd64. If we see a load to int reg followed by an int->fp move, then we can just load to the fp reg instead. Same for stores. math.Abs is now: MOVQ "".x+8(SP), AX SHLQ $1, AX SHRQ $1, AX MOVQ AX, "".~r1+16(SP) math.Copysign is now: MOVQ "".x+8(SP), AX SHLQ $1, AX SHRQ $1, AX MOVQ "".y+16(SP), CX SHRQ $63, CX SHLQ $63, CX ORQ CX, AX MOVQ AX, "".~r2+24(SP) math.Float64bits is now: MOVSD "".x+8(SP), X0 MOVSD X0, "".~r1+16(SP) (it would be nicer to use a non-SSE reg for this, nothing is perfect) And due to the fix for #21440, the inlined version of these improve as well. name old time/op new time/op delta Abs 1.38ns ± 5% 0.89ns ±10% -35.54% (p=0.000 n=10+10) Copysign 1.56ns ± 7% 1.35ns ± 6% -13.77% (p=0.000 n=9+10) Fixes #13095 Change-Id: Ibd7f2792412a6668608780b0688a77062e1f1499 Reviewed-on: https://go-review.googlesource.com/58732 Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Gobot Gobot <gobot@golang.org> Reviewed-by: Cherry Zhang <cherryyz@google.com> Reviewed-by: Ilya Tocar <ilya.tocar@intel.com>		2017-08-25 19:15:01 +00:00
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internal	cmd/compile,math: improve code generation for math.Abs	2017-08-25 19:15:01 +00:00
doc.go	cmd/compile: add mutex profiling support	2017-04-05 22:10:54 +00:00
fmt_test.go	cmd/compile: rename SSA Register.Name to Register.String	2017-08-17 21:53:08 +00:00
main.go	cmd/internal/objabi: extract shared functionality from obj	2017-04-19 00:00:09 +00:00