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cmd/compile: use power5 instructions for uint64 to float casts

Use the same technique as mips64 for these casts (CL 22835).

We could use the FCFIDU instruction for ppc64le however it seems
better to keep it the same as ppc64 for now.

Updates #15539, updates #16004.

Change-Id: I550680e485327568bf3238c4615a6cc8de6438d7
Reviewed-on: https://go-review.googlesource.com/24191
Reviewed-by: David Chase <drchase@google.com>
Run-TryBot: Michael Munday <munday@ca.ibm.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
This commit is contained in:
Michael Munday 2016-06-16 18:12:48 -04:00
parent 9e8fa1e99c
commit f3d54789f7

View File

@ -441,9 +441,8 @@ func gmove(f *gc.Node, t *gc.Node) {
gc.Regfree(&r3)
return
//warn("gmove: convert int to float not implemented: %N -> %N\n", f, t);
/*
* signed integer to float
* integer to float
*/
case gc.TINT32<<16 | gc.TFLOAT32,
gc.TINT32<<16 | gc.TFLOAT64,
@ -452,10 +451,42 @@ func gmove(f *gc.Node, t *gc.Node) {
gc.TINT16<<16 | gc.TFLOAT32,
gc.TINT16<<16 | gc.TFLOAT64,
gc.TINT8<<16 | gc.TFLOAT32,
gc.TINT8<<16 | gc.TFLOAT64:
gc.TINT8<<16 | gc.TFLOAT64,
gc.TUINT16<<16 | gc.TFLOAT32,
gc.TUINT16<<16 | gc.TFLOAT64,
gc.TUINT8<<16 | gc.TFLOAT32,
gc.TUINT8<<16 | gc.TFLOAT64,
gc.TUINT32<<16 | gc.TFLOAT32,
gc.TUINT32<<16 | gc.TFLOAT64,
gc.TUINT64<<16 | gc.TFLOAT32,
gc.TUINT64<<16 | gc.TFLOAT64:
bignodes()
// The algorithm is:
// if small enough, use native int64 -> float64 conversion,
// otherwise halve (x -> (x>>1)|(x&1)), convert, and double.
// Note: could use FCFIDU instead if target supports it.
var r1 gc.Node
gc.Regalloc(&r1, gc.Types[gc.TINT64], nil)
gmove(f, &r1)
if ft == gc.TUINT64 {
gc.Nodreg(&r2, gc.Types[gc.TUINT64], ppc64.REGTMP)
gmove(&bigi, &r2)
gins(ppc64.ACMPU, &r1, &r2)
p1 := gc.Gbranch(optoas(gc.OLT, gc.Types[gc.TUINT64]), nil, +1)
var r3 gc.Node
gc.Regalloc(&r3, gc.Types[gc.TUINT64], nil)
p2 := gins(ppc64.AANDCC, nil, &r3) // andi.
p2.Reg = r1.Reg
p2.From.Type = obj.TYPE_CONST
p2.From.Offset = 1
p3 := gins(ppc64.ASRD, nil, &r1)
p3.From.Type = obj.TYPE_CONST
p3.From.Offset = 1
gins(ppc64.AOR, &r3, &r1)
gc.Regfree(&r3)
gc.Patch(p1, gc.Pc)
}
gc.Regalloc(&r2, gc.Types[gc.TFLOAT64], t)
p1 := gins(ppc64.AMOVD, &r1, nil)
p1.To.Type = obj.TYPE_MEM
@ -467,36 +498,12 @@ func gmove(f *gc.Node, t *gc.Node) {
p1.From.Offset = -8
gins(ppc64.AFCFID, &r2, &r2)
gc.Regfree(&r1)
gmove(&r2, t)
gc.Regfree(&r2)
return
/*
* unsigned integer to float
*/
case gc.TUINT16<<16 | gc.TFLOAT32,
gc.TUINT16<<16 | gc.TFLOAT64,
gc.TUINT8<<16 | gc.TFLOAT32,
gc.TUINT8<<16 | gc.TFLOAT64,
gc.TUINT32<<16 | gc.TFLOAT32,
gc.TUINT32<<16 | gc.TFLOAT64,
gc.TUINT64<<16 | gc.TFLOAT32,
gc.TUINT64<<16 | gc.TFLOAT64:
var r1 gc.Node
gc.Regalloc(&r1, gc.Types[gc.TUINT64], nil)
gmove(f, &r1)
gc.Regalloc(&r2, gc.Types[gc.TFLOAT64], t)
p1 := gins(ppc64.AMOVD, &r1, nil)
p1.To.Type = obj.TYPE_MEM
p1.To.Reg = ppc64.REGSP
p1.To.Offset = -8
p1 = gins(ppc64.AFMOVD, nil, &r2)
p1.From.Type = obj.TYPE_MEM
p1.From.Reg = ppc64.REGSP
p1.From.Offset = -8
gins(ppc64.AFCFIDU, &r2, &r2)
gc.Regfree(&r1)
if ft == gc.TUINT64 {
p1 := gc.Gbranch(optoas(gc.OLT, gc.Types[gc.TUINT64]), nil, +1) // use CR0 here again
gc.Nodreg(&r1, gc.Types[gc.TFLOAT64], ppc64.FREGTWO)
gins(ppc64.AFMUL, &r1, &r2)
gc.Patch(p1, gc.Pc)
}
gmove(&r2, t)
gc.Regfree(&r2)
return