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| author | Ruixin Bao <ruixin.bao@ibm.com> | 2019-09-08 18:50:24 -0400 |
|---|---|---|
| committer | Michael Munday <mike.munday@ibm.com> | 2019-09-13 09:04:48 +0000 |
| commit | 98aa97806b94495847f7f7151d4453f5830f0d38 (patch) | |
| tree | c4fb2f685551832809142a50278fe31272de270f /src/cmd/compile/internal/s390x | |
| parent | 03f63654c4ce5885bf804fe242a4e15b70edc2c4 (diff) | |
| download | go-98aa97806b94495847f7f7151d4453f5830f0d38.tar.gz go-98aa97806b94495847f7f7151d4453f5830f0d38.zip | |
cmd/compile: add math/bits.Mul64 intrinsic on s390x
This change adds an intrinsic for Mul64 on s390x. To achieve that,
a new assembly instruction, MLGR, is introduced in s390x/asmz.go. This assembly
instruction directly uses an existing instruction on Z and supports multiplication
of two 64 bit unsigned integer and stores the result in two separate registers.
In this case, we require the multiplcand to be stored in register R3 and
the output result (the high and low 64 bit of the product) to be stored in
R2 and R3 respectively.
A test case is also added.
Benchmark:
name old time/op new time/op delta
Mul-18 11.1ns ± 0% 1.4ns ± 0% -87.39% (p=0.002 n=8+10)
Mul32-18 2.07ns ± 0% 2.07ns ± 0% ~ (all equal)
Mul64-18 11.1ns ± 1% 1.4ns ± 0% -87.42% (p=0.000 n=10+10)
Change-Id: Ieca6ad1f61fff9a48a31d50bbd3f3c6d9e6675c1
Reviewed-on: https://go-review.googlesource.com/c/go/+/194572
Reviewed-by: Michael Munday <mike.munday@ibm.com>
Run-TryBot: Michael Munday <mike.munday@ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Diffstat (limited to 'src/cmd/compile/internal/s390x')
| -rw-r--r-- | src/cmd/compile/internal/s390x/ssa.go | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/src/cmd/compile/internal/s390x/ssa.go b/src/cmd/compile/internal/s390x/ssa.go index fc828946b9..5acb391dcd 100644 --- a/src/cmd/compile/internal/s390x/ssa.go +++ b/src/cmd/compile/internal/s390x/ssa.go @@ -225,6 +225,19 @@ func ssaGenValue(s *gc.SSAGenState, v *ssa.Value) { v.Fatalf("input[0] and output not in same register %s", v.LongString()) } opregreg(s, v.Op.Asm(), r, v.Args[1].Reg()) + case ssa.OpS390XMLGR: + // MLGR Rx R3 -> R2:R3 + r0 := v.Args[0].Reg() + r1 := v.Args[1].Reg() + if r1 != s390x.REG_R3 { + v.Fatalf("We require the multiplcand to be stored in R3 for MLGR %s", v.LongString()) + } + p := s.Prog(s390x.AMLGR) + p.From.Type = obj.TYPE_REG + p.From.Reg = r0 + p.To.Reg = s390x.REG_R2 + p.To.Type = obj.TYPE_REG + case ssa.OpS390XFMADD, ssa.OpS390XFMADDS, ssa.OpS390XFMSUB, ssa.OpS390XFMSUBS: r := v.Reg() |