Skip to content
New issue

Have a question about this project? Sign up for a free GitHub account to open an issue and contact its maintainers and the community.

Sign up for GitHub

By clicking “Sign up for GitHub”, you agree to our terms of service and privacy statement. We’ll occasionally send you account related emails.

Already on GitHub? Sign in to your account

Jump to bottom

x86: Force result of Icomp to be in a register #11808

Merged
merged 3 commits into from Dec 14, 2022
Merged

x86: Force result of Icomp to be in a register #11808

Show file tree
Hide file tree
Changes from 1 commit
Commits
Show all changes
3 commits
Select commit Hold shift + click to select a range
71c568b
x86: Force result of Icomp to be in a register
lthls Dec 12, 2022
81dd82a
Use self#makeregs directly
lthls Dec 12, 2022
11bed79
Add Changes entry for 11803
xavierleroy Dec 14, 2022
File filter

Filter by extension

Filter by extension
Conversations
Failed to load comments.
Jump to
Jump to file
Failed to load files.
Diff view
Diff view
21 changes: 19 additions & 2 deletions asmcomp/amd64/reload.ml
View file
Open in desktop
Expand Up @@ -33,14 +33,15 @@ open Mach
Iload R R R
Istore R R
Iintop(Icomp) R R S
or S S R
or R S R
Iintop(Imul|Idiv|Imod) R R S
Iintop(Imulh) R R S
Iintop(shift) S S R
Iintop(others) R R S
or S S R
Iintop_imm(Iadd, n)/lea R R
Iintop_imm(Imul, n) R R
Iintop_imm(Icomp, n) R S
Iintop_imm(others) S S
Inegf...Idivf R R S
Ifloatofint R S
Expand All @@ -66,7 +67,18 @@ inherit Reloadgen.reload_generic as super

method! reload_operation op arg res =
match op with
| Iintop(Iadd|Isub|Iand|Ior|Ixor|Icomp _|Icheckbound) ->
| Iintop(Iadd|Isub|Iand|Ior|Ixor|Icheckbound) ->
(* One of the two arguments can reside in the stack, but not both *)
if stackp arg.(0) && stackp arg.(1)
then ([|arg.(0); self#makereg arg.(1)|], res)
else (arg, res)
| Iintop(Icomp _) ->
(* The result must be a register *)
let res =
if stackp res.(0)
then [|self#makereg res.(0)|]
else res
in
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

makereg is a no-op if the argument is already a register, and there's makeregs to handle arrays of regs. Proposed simplification:

Suggested change
(* The result must be a register *)
let res =
if stackp res.(0)
then [|self#makereg res.(0)|]
else res
in
(* The result must be a register (PR#11083) *)
let res = self#makeregs res in

Copy link
Contributor Author

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

I didn't think of calling makereg even in the register case, but I didn't use makeregs because it wasn't exported. I assume that there's no harm in exporting it though, so I've pushed a patch with your suggestion.

(* One of the two arguments can reside in the stack, but not both *)
if stackp arg.(0) && stackp arg.(1)
then ([|arg.(0); self#makereg arg.(1)|], res)
Expand All @@ -80,6 +92,11 @@ method! reload_operation op arg res =
if stackp arg.(0)
then (let r = self#makereg arg.(0) in ([|r|], [|r|]))
else (arg, res)
| Iintop_imm(Icomp _, _) ->
(* The result must be in a register *)
if stackp res.(0)
then (arg, [|self#makereg res.(0)|])
else (arg, res)
Copy link
Contributor

Choose a reason for hiding this comment

The reason will be displayed to describe this comment to others. Learn more.

Similar suggestion:

Suggested change
| Iintop_imm(Icomp _, _) ->
(* The result must be in a register *)
if stackp res.(0)
then (arg, [|self#makereg res.(0)|])
else (arg, res)
| Iintop_imm(Icomp _, _) ->
(* The result must be in a register (PR#11083) *)
(arg, self#makeregs res)

| Iintop(Imulh | Idiv | Imod | Ilsl | Ilsr | Iasr)
| Iintop_imm(_, _) ->
(* The argument(s) and results can be either in register or on stack *)
Expand Down
18 changes: 17 additions & 1 deletion asmcomp/i386/reload.ml
View file
Open in desktop
Expand Up @@ -40,7 +40,18 @@ method! makereg r =

method! reload_operation op arg res =
match op with
Iintop(Iadd|Isub|Iand|Ior|Ixor|Icomp _|Icheckbound) ->
Iintop(Iadd|Isub|Iand|Ior|Ixor|Icheckbound) ->
(* One of the two arguments can reside in the stack *)
if stackp arg.(0) && stackp arg.(1)
then ([|arg.(0); self#makereg arg.(1)|], res)
else (arg, res)
| Iintop(Icomp _) ->
(* The result must be a register *)
let res =
if stackp res.(0)
then [|self#makereg res.(0)|]
else res
in
(* One of the two arguments can reside in the stack *)
if stackp arg.(0) && stackp arg.(1)
then ([|arg.(0); self#makereg arg.(1)|], res)
Expand All @@ -60,6 +71,11 @@ method! reload_operation op arg res =
if stackp arg.(0)
then let r = self#makereg arg.(0) in ([|r|], [|r|])
else (arg, res)
| Iintop_imm(Icomp _, _) ->
(* The result must be in a register *)
if stackp res.(0)
then (arg, [|self#makereg res.(0)|])
else (arg, res)
| Iintop(Imulh | Ilsl | Ilsr | Iasr) | Iintop_imm(_, _)
| Ifloatofint | Iintoffloat | Ispecific(Ipush) ->
(* The argument(s) can be either in register or on stack *)
Expand Down