https://gcc.gnu.org/g:69669180d29cc420b1b1ac86530a4f9573748d81
commit r16-285-g69669180d29cc420b1b1ac86530a4f9573748d81
Author: Uros Bizjak <ubiz...@gmail.com>
Date: Tue Apr 29 18:08:05 2025 +0200
i386: Disable string insn from non-default AS for Pmode != word_mode
[PR111657]
0x67 prefix is applied before segment register. That is in
rep movsq %gs:(%esi), (%edi)
the address is %gs + %esi. In case Pmode != word_mode (x32 with a default
-maddress-mode=short) instructions should not allow segment override
prefixes.
Also, remove explicit addr32 prefix from asm templates because address
mode can be determined from explicit instruction operands. Also note that
Pmode != word_mode only with TARGET_64BIT, so the check in
ix86_print_operand
is not needed.
PR target/111657
gcc/ChangeLog:
* config/i386/i386-expand.cc (alg_usable_p): For Pmode != word_mode
reject rep_prefix_{1,4,8}_byte algorithms with src_as in the
non-default address space.
* config/i386/i386-protos.h (ix86_check_movs): New prototype.
* config/i386/i386.cc (ix86_check_movs): New function.
(ix86_print_operand) [case '^']: Remove excess check for
TARGET_64BIT.
* config/i386/i386.md (strmov): For Pmode != word_mode expand with
gen_strmov_single only when operands[3] (source) is in the default
address space.
(*strmovdi_rex_1) Use ix86_check_movs. Remove %^ from asm template.
(*strmovsi_1): Ditto.
(*strmovhi_1): DItto.
(*strmovqi_1): Ditto.
(*rep_movdi_rex64): Ditto.
(*rep_movsi): Ditto.
(*rep_movqi): Ditto.
gcc/testsuite/ChangeLog:
* gcc.target/i386/pr111657-1.c: Check that segment override is not
generated for "rep movsq" for x32 target.
Diff:
---
gcc/config/i386/i386-expand.cc | 3 ++-
gcc/config/i386/i386-protos.h | 1 +
gcc/config/i386/i386.cc | 23 +++++++++++++++++-
gcc/config/i386/i386.md | 39 +++++++++++++-----------------
gcc/testsuite/gcc.target/i386/pr111657-1.c | 3 ++-
5 files changed, 44 insertions(+), 25 deletions(-)
diff --git a/gcc/config/i386/i386-expand.cc b/gcc/config/i386/i386-expand.cc
index f1cc85b4531c..7f0fdb6fa9e9 100644
--- a/gcc/config/i386/i386-expand.cc
+++ b/gcc/config/i386/i386-expand.cc
@@ -8933,7 +8933,8 @@ alg_usable_p (enum stringop_alg alg, bool memset,
if (fixed_regs[CX_REG]
|| fixed_regs[DI_REG]
|| (memset ? fixed_regs[AX_REG] : fixed_regs[SI_REG])
- || !ADDR_SPACE_GENERIC_P (dst_as))
+ || !ADDR_SPACE_GENERIC_P (dst_as)
+ || !(ADDR_SPACE_GENERIC_P (src_as) || Pmode == word_mode))
return false;
}
return true;
diff --git a/gcc/config/i386/i386-protos.h b/gcc/config/i386/i386-protos.h
index c59b5a67e3a5..e85b925704ba 100644
--- a/gcc/config/i386/i386-protos.h
+++ b/gcc/config/i386/i386-protos.h
@@ -186,6 +186,7 @@ extern void ix86_expand_v2di_ashiftrt (rtx[]);
extern rtx ix86_replace_reg_with_reg (rtx, rtx, rtx);
extern rtx ix86_find_base_term (rtx);
extern bool ix86_check_movabs (rtx, int);
+extern bool ix86_check_movs (rtx, int);
extern bool ix86_check_no_addr_space (rtx);
extern void ix86_split_idivmod (machine_mode, rtx[], bool);
extern bool ix86_hardreg_mov_ok (rtx, rtx);
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index bfd9cac215ad..2f8403381384 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -5180,6 +5180,27 @@ ix86_check_movabs (rtx insn, int opnum)
return volatile_ok || !MEM_VOLATILE_P (mem);
}
+/* Return true if XVECEXP idx of INSN satisfies MOVS arguments. */
+bool
+ix86_check_movs (rtx insn, int idx)
+{
+ rtx pat = PATTERN (insn);
+ gcc_assert (GET_CODE (pat) == PARALLEL);
+
+ rtx set = XVECEXP (pat, 0, idx);
+ gcc_assert (GET_CODE (set) == SET);
+
+ rtx dst = SET_DEST (set);
+ gcc_assert (MEM_P (dst));
+
+ rtx src = SET_SRC (set);
+ gcc_assert (MEM_P (src));
+
+ return (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (dst))
+ && (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (src))
+ || Pmode == word_mode));
+}
+
/* Return false if INSN contains a MEM with a non-default address space. */
bool
ix86_check_no_addr_space (rtx insn)
@@ -14296,7 +14317,7 @@ ix86_print_operand (FILE *file, rtx x, int code)
return;
case '^':
- if (TARGET_64BIT && Pmode != word_mode)
+ if (Pmode != word_mode)
fputs ("addr32 ", file);
return;
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 962e7ab92aa8..44ee94a3e419 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -25599,7 +25599,9 @@
* since string insns cannot override the destination segment. */
if ((TARGET_SINGLE_STRINGOP || optimize_insn_for_size_p ())
&& !(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (operands[1])))
+ && ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (operands[1]))
+ && (ADDR_SPACE_GENERIC_P (MEM_ADDR_SPACE (operands[3]))
+ || Pmode == word_mode))
{
emit_insn (gen_strmov_singleop (operands[0], operands[1],
operands[2], operands[3],
@@ -25634,15 +25636,14 @@
(const_int 8)))]
"TARGET_64BIT
&& !(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+ && ix86_check_movs (insn, 0)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 0);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^movsq\t{%1, %0|%0, %1}";
+ return "movsq\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "memory" "both")
@@ -25658,15 +25659,14 @@
(plus:P (match_dup 3)
(const_int 4)))]
"!(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+ && ix86_check_movs (insn, 0)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 0);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^movs{l|d}\t{%1, %0|%0, %1}";
+ return "movs{l|d}\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "memory" "both")
@@ -25682,15 +25682,14 @@
(plus:P (match_dup 3)
(const_int 2)))]
"!(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+ && ix86_check_movs (insn, 0)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 0);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^movsw\t{%1, %0|%0, %1}";
+ return "movsw\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "memory" "both")
@@ -25706,15 +25705,14 @@
(plus:P (match_dup 3)
(const_int 1)))]
"!(fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 0))))"
+ && ix86_check_movs (insn, 0)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 0);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^movsb\t{%1, %0|%0, %1}";
+ return "movsb\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "memory" "both")
@@ -25754,15 +25752,14 @@
(use (match_dup 5))]
"TARGET_64BIT
&& !(fixed_regs[CX_REG] || fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 3))))"
+ && ix86_check_movs (insn, 3)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 3);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^rep{%;} movsq\t{%1, %0|%0, %1}";
+ return "rep{%;} movsq\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
@@ -25782,15 +25779,14 @@
(mem:BLK (match_dup 4)))
(use (match_dup 5))]
"!(fixed_regs[CX_REG] || fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 3))))"
+ && ix86_check_movs (insn, 3)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 3);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^rep{%;} movs{l|d}\t{%1, %0|%0, %1}";
+ return "rep{%;} movs{l|d}\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
@@ -25808,15 +25804,14 @@
(mem:BLK (match_dup 4)))
(use (match_dup 5))]
"!(fixed_regs[CX_REG] || fixed_regs[SI_REG] || fixed_regs[DI_REG])
- && ADDR_SPACE_GENERIC_P
- (MEM_ADDR_SPACE (SET_DEST (XVECEXP (PATTERN (insn), 0, 3))))"
+ && ix86_check_movs (insn, 3)"
{
rtx exp = XVECEXP (PATTERN (insn), 0, 3);
operands[0] = SET_DEST (exp);
operands[1] = SET_SRC (exp);
- return "%^rep{%;} movsb\t{%1, %0|%0, %1}";
+ return "rep{%;} movsb\t{%1, %0|%0, %1}";
}
[(set_attr "type" "str")
(set_attr "prefix_rep" "1")
diff --git a/gcc/testsuite/gcc.target/i386/pr111657-1.c
b/gcc/testsuite/gcc.target/i386/pr111657-1.c
index 69117b72cdf1..99acd1f68393 100644
--- a/gcc/testsuite/gcc.target/i386/pr111657-1.c
+++ b/gcc/testsuite/gcc.target/i386/pr111657-1.c
@@ -8,4 +8,5 @@ struct a { uword arr[30]; };
__seg_gs struct a m;
void bar (struct a *dst) { *dst = m; }
-/* { dg-final { scan-assembler "rep\[; \t\]+movs(l|q)\[ \t\]+%gs:" } } */
+/* { dg-final { scan-assembler "rep\[; \t\]+movs(l|q)\[ \t\]+%gs:" { target {
! x32 } } } } */
+/* { dg-final { scan-assembler-not "rep\[; \t\]+movs(l|q)\[ \t\]+%gs:" {
target x32 } } } */
