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cmd/compile/internal, cmd/internal/obj/ppc64: generate new count trailing zeros instructions on POWER9

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This change adds new POWER9 instructions for counting trailing zeros (CNTTZW/CNTTZD)
to the assembler and generates them in SSA when GOPPC64=power9.

name                 old time/op  new time/op  delta
TrailingZeros-160    1.59ns ±20%  1.45ns ±10%  -8.81%  (p=0.000 n=14+13)
TrailingZeros8-160   1.55ns ±23%  1.62ns ±44%    ~     (p=0.593 n=13+15)
TrailingZeros16-160  1.78ns ±23%  1.62ns ±38%  -9.31%  (p=0.003 n=14+14)
TrailingZeros32-160  1.64ns ±10%  1.49ns ± 9%  -9.15%  (p=0.000 n=13+14)
TrailingZeros64-160  1.53ns ± 6%  1.45ns ± 5%  -5.38%  (p=0.000 n=15+13)

Change-Id: I365e6ff79f3ce4d8ebe089a6a86b1771853eb596
Reviewed-on: https://go-review.googlesource.com/c/go/+/167517
Reviewed-by: Lynn Boger <laboger@linux.vnet.ibm.com>
This commit is contained in:
Carlos Eduardo Seo 2019-02-08 16:18:12 -02:00
parent 23b476a3c8
commit 3023d7da49
9 changed files with 109 additions and 19 deletions
Download patch file Download diff file Expand all files Collapse all files

24
test/codegen/mathbits.go
View file

@ -261,8 +261,10 @@ func TrailingZeros(n uint) int {
// arm:"CLZ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64:"ANDN","POPCNTD"
// ppc64le:"ANDN","POPCNTD"
// ppc64/power8:"ANDN","POPCNTD"
// ppc64le/power8:"ANDN","POPCNTD"
// ppc64/power9: "CNTTZD"
// ppc64le/power9: "CNTTZD"
// wasm:"I64Ctz"
return bits.TrailingZeros(n)
}
@ -271,8 +273,10 @@ func TrailingZeros64(n uint64) int {
// amd64:"BSFQ","MOVL\t\\$64","CMOVQEQ"
// arm64:"RBIT","CLZ"
// s390x:"FLOGR"
// ppc64:"ANDN","POPCNTD"
// ppc64le:"ANDN","POPCNTD"
// ppc64/power8:"ANDN","POPCNTD"
// ppc64le/power8:"ANDN","POPCNTD"
// ppc64/power9: "CNTTZD"
// ppc64le/power9: "CNTTZD"
// wasm:"I64Ctz"
return bits.TrailingZeros64(n)
}
@ -282,8 +286,10 @@ func TrailingZeros32(n uint32) int {
// arm:"CLZ"
// arm64:"RBITW","CLZW"
// s390x:"FLOGR","MOVWZ"
// ppc64:"ANDN","POPCNTW"
// ppc64le:"ANDN","POPCNTW"
// ppc64/power8:"ANDN","POPCNTW"
// ppc64le/power8:"ANDN","POPCNTW"
// ppc64/power9: "CNTTZW"
// ppc64le/power9: "CNTTZW"
// wasm:"I64Ctz"
return bits.TrailingZeros32(n)
}
@ -293,8 +299,10 @@ func TrailingZeros16(n uint16) int {
// arm:"ORR\t\\$65536","CLZ",-"MOVHU\tR"
// arm64:"ORR\t\\$65536","RBITW","CLZW",-"MOVHU\tR",-"RBIT\t",-"CLZ\t"
// s390x:"FLOGR","OR\t\\$65536"
// ppc64:"POPCNTD","OR\\t\\$65536"
// ppc64le:"POPCNTD","OR\\t\\$65536"
// ppc64/power8:"POPCNTD","OR\\t\\$65536"
// ppc64le/power8:"POPCNTD","OR\\t\\$65536"
// ppc64/power9:"CNTTZD","OR\\t\\$65536"
// ppc64le/power9:"CNTTZD","OR\\t\\$65536"
// wasm:"I64Ctz"
return bits.TrailingZeros16(n)
}