Add Float64Round operator.

Add Float64Floor, Float64Ceil, Float64RoundTruncate, Float64RoundTiesAway operators.

These operators are not supported by any backends yet, and a backend is free to not support them.

R=bmeurer@chromium.org
TEST=unittest/machine-operator

Committed: https://code.google.com/p/v8/source/detail?r=24874

[sigurds, 2014-10-22 11:00:56]

PTAL.

[sigurds, 2014-10-22 13:37:40]

sigurds@chromium.org changed reviewers:
+ bmeurer@chromium.org

[sigurds, 2014-10-22 13:37:41]

As discussed. PTAL again :)

[titzer, 2014-10-22 14:05:42]

https://codereview.chromium.org/668173002/diff/40001/src/compiler/machine-ope...
File src/compiler/machine-operator.h (right):

https://codereview.chromium.org/668173002/diff/40001/src/compiler/machine-ope...
src/compiler/machine-operator.h:57: kRoundDown,
A little confusing here.

These rounding modes map to operators, correct? Then why do we need the separate
enum if it is not a parameter to the operator?

https://codereview.chromium.org/668173002/diff/40001/src/compiler/machine-ope...
src/compiler/machine-operator.h:63: #define BACKEND_SPECIFIC_OPS(V) \
Can we try to avoid the higher order macro stuff here? It's really hard to tell
what methods are available on the MachineOperatorBuilder like this.

[sigurds, 2014-10-22 14:24:50]

Adressed changes. Please take a look again.

https://codereview.chromium.org/668173002/diff/40001/src/compiler/machine-ope...
File src/compiler/machine-operator.h (right):

https://codereview.chromium.org/668173002/diff/40001/src/compiler/machine-ope...
src/compiler/machine-operator.h:57: kRoundDown,
On 2014/10/22 14:05:42, titzer wrote:
> A little confusing here.
> 
> These rounding modes map to operators, correct? Then why do we need the
separate
> enum if it is not a parameter to the operator?

I thought it was cleaner to have one op + rounding mode instead of several ops
here. Changed it in the last upload. Please tell me which you think is better.

https://codereview.chromium.org/668173002/diff/40001/src/compiler/machine-ope...
src/compiler/machine-operator.h:63: #define BACKEND_SPECIFIC_OPS(V) \
On 2014/10/22 14:05:42, titzer wrote:
> Can we try to avoid the higher order macro stuff here? It's really hard to
tell
> what methods are available on the MachineOperatorBuilder like this.
> 

Done.

[Benedikt Meurer, 2014-10-23 07:11:15]

https://codereview.chromium.org/668173002/diff/60001/src/compiler/instruction...
File src/compiler/instruction-selector.h (right):

https://codereview.chromium.org/668173002/diff/60001/src/compiler/instruction...
src/compiler/instruction-selector.h:91: static SupportedOperators
GetSupportedOperators();
This should take a CpuFeatures parameter, because we certainly depend on the CPU
features available.

https://codereview.chromium.org/668173002/diff/60001/src/compiler/machine-ope...
File src/compiler/machine-operator.h (right):

https://codereview.chromium.org/668173002/diff/60001/src/compiler/machine-ope...
src/compiler/machine-operator.h:55: enum SupportedOperator {
I'd not name it SupportedOperator, but rather move it to
MachineOperatorBuilder::Flags, because it's not only about the availability of
operators but also about their behavior.

[sigurds, 2014-10-23 10:37:57]

Thanks for the comments so far! PTAL again :)

https://codereview.chromium.org/668173002/diff/60001/src/compiler/instruction...
File src/compiler/instruction-selector.h (right):

https://codereview.chromium.org/668173002/diff/60001/src/compiler/instruction...
src/compiler/instruction-selector.h:91: static SupportedOperators
GetSupportedOperators();
On 2014/10/23 07:11:14, Benedikt Meurer wrote:
> This should take a CpuFeatures parameter, because we certainly depend on the
CPU
> features available.

As discussed, I'll add a todo.

https://codereview.chromium.org/668173002/diff/60001/src/compiler/machine-ope...
File src/compiler/machine-operator.h (right):

https://codereview.chromium.org/668173002/diff/60001/src/compiler/machine-ope...
src/compiler/machine-operator.h:55: enum SupportedOperator {
On 2014/10/23 07:11:14, Benedikt Meurer wrote:
> I'd not name it SupportedOperator, but rather move it to
> MachineOperatorBuilder::Flags, because it's not only about the availability of
> operators but also about their behavior.

Done.

[Benedikt Meurer, 2014-10-23 11:04:57]

https://codereview.chromium.org/668173002/diff/100001/src/compiler/instructio...
File src/compiler/instruction-selector.h (right):

https://codereview.chromium.org/668173002/diff/100001/src/compiler/instructio...
src/compiler/instruction-selector.h:89: static MachineOperatorBuilder::Flags
GetSupportedOperators();
s,GetSupportedOperators,SupportedMachineOperatorFlags,

https://codereview.chromium.org/668173002/diff/100001/src/compiler/machine-op...
File src/compiler/machine-operator.h (right):

https://codereview.chromium.org/668173002/diff/100001/src/compiler/machine-op...
src/compiler/machine-operator.h:62: enum Flag : unsigned int {
enum class Flag : unsigned {...}

https://codereview.chromium.org/668173002/diff/100001/src/compiler/machine-op...
src/compiler/machine-operator.h:69: typedef base::Flags<Flag, unsigned int>
Flags;
s,unsigned int,unsigned,

[sigurds, 2014-10-23 11:15:56]

PTAL again :)

https://codereview.chromium.org/668173002/diff/100001/src/compiler/instructio...
File src/compiler/instruction-selector.h (right):

https://codereview.chromium.org/668173002/diff/100001/src/compiler/instructio...
src/compiler/instruction-selector.h:89: static MachineOperatorBuilder::Flags
GetSupportedOperators();
On 2014/10/23 11:04:57, Benedikt Meurer wrote:
> s,GetSupportedOperators,SupportedMachineOperatorFlags,

Done.

https://codereview.chromium.org/668173002/diff/100001/src/compiler/machine-op...
File src/compiler/machine-operator.h (right):

https://codereview.chromium.org/668173002/diff/100001/src/compiler/machine-op...
src/compiler/machine-operator.h:62: enum Flag : unsigned int {
On 2014/10/23 11:04:57, Benedikt Meurer wrote:
> enum class Flag : unsigned {...}

Done. Had to intro a static_cast in flags.h.

https://codereview.chromium.org/668173002/diff/100001/src/compiler/machine-op...
src/compiler/machine-operator.h:69: typedef base::Flags<Flag, unsigned int>
Flags;
On 2014/10/23 11:04:57, Benedikt Meurer wrote:
> s,unsigned int,unsigned,

Done.

[Benedikt Meurer, 2014-10-24 03:58:58]

LGTM if you can explain to me why a static_cast in flags.h is needed.

[sigurds, 2014-10-24 09:36:02]

On 2014/10/24 03:58:58, Benedikt Meurer wrote:
> LGTM if you can explain to me why a static_cast in flags.h is needed.

enum classes don't implicity convert to int; they have to be static_cast.

[sigurds, 2014-10-24 13:07:09]

Committed patchset #8 (id:140001) manually as 24874 (presubmit successful).