i386: Add "z" constraint for symbolic address/label reference [PR105576]
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Commit Message
Printing the raw symbol is useful in inline asm (e.g. in C++ to get the
mangled name). Similar constraints are available in other targets (e.g.
"S" for aarch64/riscv, "Cs" for m68k).
There isn't a good way for x86 yet, e.g. "i" doesn't work for
PIC/-mcmodel=large. This patch adds "z".
gcc/ChangeLog:
PR target/105576
* config/i386/constraints.md: Define constraint 'z'.
* doc/md.texi: Document it.
gcc/testsuite/ChangeLog:
* gcc.target/i386/asm-raw-symbol.c: New testcase.
---
gcc/config/i386/constraints.md | 5 ++++-
gcc/doc/md.texi | 4 ++++
gcc/testsuite/gcc.target/i386/asm-raw-symbol.c | 13 +++++++++++++
3 files changed, 21 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
Comments
On Thu, Jan 11, 2024 at 4:44 AM Fangrui Song <maskray@google.com> wrote:
>
> Printing the raw symbol is useful in inline asm (e.g. in C++ to get the
> mangled name). Similar constraints are available in other targets (e.g.
> "S" for aarch64/riscv, "Cs" for m68k).
>
> There isn't a good way for x86 yet, e.g. "i" doesn't work for
> PIC/-mcmodel=large. This patch adds "z".
Please use W-prefixed multi-letter constraint name.
Uros.
>
> gcc/ChangeLog:
>
> PR target/105576
> * config/i386/constraints.md: Define constraint 'z'.
> * doc/md.texi: Document it.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/asm-raw-symbol.c: New testcase.
> ---
> gcc/config/i386/constraints.md | 5 ++++-
> gcc/doc/md.texi | 4 ++++
> gcc/testsuite/gcc.target/i386/asm-raw-symbol.c | 13 +++++++++++++
> 3 files changed, 21 insertions(+), 1 deletion(-)
> create mode 100644 gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
>
> diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
> index 0c6e662df25..64330dfdf01 100644
> --- a/gcc/config/i386/constraints.md
> +++ b/gcc/config/i386/constraints.md
> @@ -19,7 +19,6 @@
>
> ;;; Unused letters:
> ;;; H
> -;;; z
>
> ;; Integer register constraints.
> ;; It is not necessary to define 'r' here.
> @@ -438,3 +437,7 @@ (define_constraint "je"
> "@internal constant that do not allow any unspec global offsets"
> (and (match_operand 0 "x86_64_immediate_operand")
> (match_test "!x86_poff_operand_p (op)")))
> +
> +(define_constraint "z"
> + "A symbolic reference or label reference."
> + (match_code "const,symbol_ref,label_ref"))
> diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
> index 47a87d6ceec..bbfec024311 100644
> --- a/gcc/doc/md.texi
> +++ b/gcc/doc/md.texi
> @@ -4286,6 +4286,10 @@ VSIB address operand.
> @item Ts
> Address operand without segment register.
>
> +@item z
> +A symbolic reference or label reference.
> +You can use the @code{%p} modifier to print the raw symbol.
> +
> @end table
>
> @item Xstormy16---@file{config/stormy16/stormy16.h}
> diff --git a/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
> new file mode 100644
> index 00000000000..ce88f3baee6
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +
> +extern int var;
> +
> +void
> +func (void)
> +{
> + __asm__ ("@ %p0" : : "z" (func));
> + __asm__ ("@ %p0" : : "z" (&var + 1));
> +}
> +
> +/* { dg-final { scan-assembler "@ func" } } */
> +/* { dg-final { scan-assembler "@ var\\+4" } } */
> --
> 2.43.0.275.g3460e3d667-goog
>
On 2024-01-11, Uros Bizjak wrote:
>On Thu, Jan 11, 2024 at 4:44 AM Fangrui Song <maskray@google.com> wrote:
>>
>> Printing the raw symbol is useful in inline asm (e.g. in C++ to get the
>> mangled name). Similar constraints are available in other targets (e.g.
>> "S" for aarch64/riscv, "Cs" for m68k).
>>
>> There isn't a good way for x86 yet, e.g. "i" doesn't work for
>> PIC/-mcmodel=large. This patch adds "z".
>
>Please use W-prefixed multi-letter constraint name.
>
>Uros.
Sounds good. How about "Ws"?
(I've asked overseers@gcc.gnu.org whether I can get gcc access (I
already have binutils-gdb/glibc access), so that I can land approved
patches myself in the future)
From ad7bf3dce026bf226e22ab709c9326c611a4b745 Mon Sep 17 00:00:00 2001
From: Fangrui Song <maskray@google.com>
Date: Wed, 10 Jan 2024 18:49:45 -0800
Subject: [PATCH] i386: Add "Ws" constraint for symbolic address/label
reference [PR105576]
Printing the raw symbol is useful in inline asm (e.g. in C++ to get the
mangled name). Similar constraints are available in other targets (e.g.
"S" for aarch64/riscv, "Cs" for m68k).
There isn't a good way for x86 yet, e.g. "i" doesn't work for
PIC/-mcmodel=large. This patch adds "Ws". Here are possible use cases:
```
namespace ns { extern int var; }
asm (".pushsection .xxx,\"aw\"; .dc.a %0; .popsection" :: "S"(&var));
asm (".reloc ., BFD_RELOC_NONE, %0" :: "S"(&var));
```
gcc/ChangeLog:
PR target/105576
* config/i386/constraints.md: Define constraint "Ws".
* doc/md.texi: Document it.
gcc/testsuite/ChangeLog:
* gcc.target/i386/asm-raw-symbol.c: New testcase.
---
gcc/config/i386/constraints.md | 4 ++++
gcc/doc/md.texi | 4 ++++
gcc/testsuite/gcc.target/i386/asm-raw-symbol.c | 13 +++++++++++++
3 files changed, 21 insertions(+)
create mode 100644 gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
index 0c6e662df25..280e4c8e36c 100644
--- a/gcc/config/i386/constraints.md
+++ b/gcc/config/i386/constraints.md
@@ -348,6 +348,10 @@ (define_constraint "Wf"
to double word size."
(match_operand 0 "x86_64_dwzext_immediate_operand"))
+(define_constraint "Ws"
+ "A symbolic reference or label reference."
+ (match_code "const,symbol_ref,label_ref"))
+
(define_constraint "Z"
"32-bit unsigned integer constant, or a symbolic reference known
to fit that range (for immediate operands in zero-extending x86-64
diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
index 47a87d6ceec..b0c61925120 100644
--- a/gcc/doc/md.texi
+++ b/gcc/doc/md.texi
@@ -4275,6 +4275,10 @@ require non-@code{VOIDmode} immediate operands).
128-bit integer constant where both the high and low 64-bit word
satisfy the @code{e} constraint.
+@item Ws
+A symbolic reference or label reference.
+You can use the @code{%p} modifier to print the raw symbol.
+
@item Z
32-bit unsigned integer constant, or a symbolic reference known
to fit that range (for immediate operands in zero-extending x86-64
diff --git a/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
new file mode 100644
index 00000000000..b7854567dd9
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+extern int var;
+
+void
+func (void)
+{
+ __asm__ ("@ %p0" : : "Ws" (func));
+ __asm__ ("@ %p0" : : "Ws" (&var + 1));
+}
+
+/* { dg-final { scan-assembler "@ func" } } */
+/* { dg-final { scan-assembler "@ var\\+4" } } */
On Thu, Jan 11, 2024 at 9:33 AM Fangrui Song <maskray@google.com> wrote:
>
> On 2024-01-11, Uros Bizjak wrote:
> >On Thu, Jan 11, 2024 at 4:44 AM Fangrui Song <maskray@google.com> wrote:
> >>
> >> Printing the raw symbol is useful in inline asm (e.g. in C++ to get the
> >> mangled name). Similar constraints are available in other targets (e.g.
> >> "S" for aarch64/riscv, "Cs" for m68k).
> >>
> >> There isn't a good way for x86 yet, e.g. "i" doesn't work for
> >> PIC/-mcmodel=large. This patch adds "z".
> >
> >Please use W-prefixed multi-letter constraint name.
> >
> >Uros.
>
> Sounds good. How about "Ws"?
Yes, LGTM.
Thanks,
Uros.
>
> (I've asked overseers@gcc.gnu.org whether I can get gcc access (I
> already have binutils-gdb/glibc access), so that I can land approved
> patches myself in the future)
>
>
> From ad7bf3dce026bf226e22ab709c9326c611a4b745 Mon Sep 17 00:00:00 2001
> From: Fangrui Song <maskray@google.com>
> Date: Wed, 10 Jan 2024 18:49:45 -0800
> Subject: [PATCH] i386: Add "Ws" constraint for symbolic address/label
> reference [PR105576]
>
> Printing the raw symbol is useful in inline asm (e.g. in C++ to get the
> mangled name). Similar constraints are available in other targets (e.g.
> "S" for aarch64/riscv, "Cs" for m68k).
>
> There isn't a good way for x86 yet, e.g. "i" doesn't work for
> PIC/-mcmodel=large. This patch adds "Ws". Here are possible use cases:
>
> ```
> namespace ns { extern int var; }
> asm (".pushsection .xxx,\"aw\"; .dc.a %0; .popsection" :: "S"(&var));
> asm (".reloc ., BFD_RELOC_NONE, %0" :: "S"(&var));
> ```
>
> gcc/ChangeLog:
>
> PR target/105576
> * config/i386/constraints.md: Define constraint "Ws".
> * doc/md.texi: Document it.
>
> gcc/testsuite/ChangeLog:
>
> * gcc.target/i386/asm-raw-symbol.c: New testcase.
> ---
> gcc/config/i386/constraints.md | 4 ++++
> gcc/doc/md.texi | 4 ++++
> gcc/testsuite/gcc.target/i386/asm-raw-symbol.c | 13 +++++++++++++
> 3 files changed, 21 insertions(+)
> create mode 100644 gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
>
> diff --git a/gcc/config/i386/constraints.md b/gcc/config/i386/constraints.md
> index 0c6e662df25..280e4c8e36c 100644
> --- a/gcc/config/i386/constraints.md
> +++ b/gcc/config/i386/constraints.md
> @@ -348,6 +348,10 @@ (define_constraint "Wf"
> to double word size."
> (match_operand 0 "x86_64_dwzext_immediate_operand"))
>
> +(define_constraint "Ws"
> + "A symbolic reference or label reference."
> + (match_code "const,symbol_ref,label_ref"))
> +
> (define_constraint "Z"
> "32-bit unsigned integer constant, or a symbolic reference known
> to fit that range (for immediate operands in zero-extending x86-64
> diff --git a/gcc/doc/md.texi b/gcc/doc/md.texi
> index 47a87d6ceec..b0c61925120 100644
> --- a/gcc/doc/md.texi
> +++ b/gcc/doc/md.texi
> @@ -4275,6 +4275,10 @@ require non-@code{VOIDmode} immediate operands).
> 128-bit integer constant where both the high and low 64-bit word
> satisfy the @code{e} constraint.
>
> +@item Ws
> +A symbolic reference or label reference.
> +You can use the @code{%p} modifier to print the raw symbol.
> +
> @item Z
> 32-bit unsigned integer constant, or a symbolic reference known
> to fit that range (for immediate operands in zero-extending x86-64
> diff --git a/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
> new file mode 100644
> index 00000000000..b7854567dd9
> --- /dev/null
> +++ b/gcc/testsuite/gcc.target/i386/asm-raw-symbol.c
> @@ -0,0 +1,13 @@
> +/* { dg-do compile } */
> +
> +extern int var;
> +
> +void
> +func (void)
> +{
> + __asm__ ("@ %p0" : : "Ws" (func));
> + __asm__ ("@ %p0" : : "Ws" (&var + 1));
> +}
> +
> +/* { dg-final { scan-assembler "@ func" } } */
> +/* { dg-final { scan-assembler "@ var\\+4" } } */
> --
> 2.43.0.275.g3460e3d667-goog
>
@@ -19,7 +19,6 @@
;;; Unused letters:
;;; H
-;;; z
;; Integer register constraints.
;; It is not necessary to define 'r' here.
@@ -438,3 +437,7 @@ (define_constraint "je"
"@internal constant that do not allow any unspec global offsets"
(and (match_operand 0 "x86_64_immediate_operand")
(match_test "!x86_poff_operand_p (op)")))
+
+(define_constraint "z"
+ "A symbolic reference or label reference."
+ (match_code "const,symbol_ref,label_ref"))
@@ -4286,6 +4286,10 @@ VSIB address operand.
@item Ts
Address operand without segment register.
+@item z
+A symbolic reference or label reference.
+You can use the @code{%p} modifier to print the raw symbol.
+
@end table
@item Xstormy16---@file{config/stormy16/stormy16.h}
new file mode 100644
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+
+extern int var;
+
+void
+func (void)
+{
+ __asm__ ("@ %p0" : : "z" (func));
+ __asm__ ("@ %p0" : : "z" (&var + 1));
+}
+
+/* { dg-final { scan-assembler "@ func" } } */
+/* { dg-final { scan-assembler "@ var\\+4" } } */