Thanks, this it the patch I'm going to check-in.
Richard Sandiford <richard.sandif...@arm.com> 于2024年6月13日周四 17:04写道：
>
> Hongyu Wang <hongyu.w...@intel.com> writes:
> > Hi,
> >
> > In cfgexpand, there is an optimization for branch which tests
> > targetm.gen_ccmp_first == NULL. However for target like x86-64, the
> > hook was implemented but it does not indicate that ccmp was enabled.
> > Add a new target hook TARGET_HAVE_CCMP and replace the middle-end
> > check for the existance of gen_ccmp_first to avoid misoptimization.
> >
> > This fixes PR115370 that have suboptimal codegen, also I checked the
> > znver2 binary for 526 and it will have same binary as the one before
> > the CCMP support patch r15-1058, so suppose it could also fix PR115463.
>
> It's unfortunate that we can't simply try expanding ccmp and seeing
> whether it works, but I agree that that isn't possible for the
> cfgexpand.cc change.
>
> The expr.cc change shouldn't be needed, but I agree it's more consistent
> to change both places in the same way.
>
> > Bootstrapped/regtested on x86-64-pc-linux-gnu and aarch64-none-linux-gnu.
> >
> > Ok for trunk?
> >
> > gcc/ChangeLog:
> >
> > PR target/115370
> > PR target/115463
> > * cfgexpand.cc (expand_gimple_cond): Call targetm.have_ccmp
> > instead of checking if targetm.gen_ccmp_first exists.
> > * expr.cc (expand_expr_real_gassign): Likewise.
> > * config/i386/i386.cc (ix86_have_ccmp): New target hook to
> > check if APX_CCMP enabled.
> > (TARGET_HAVE_CCMP): Define.
> > * doc/tm.texi: Add TARGET_HAVE_CCMP.
> > * doc/tm.texi.in: Regenerated.
> > * target.def (TARGET_HAVE_CCMP): New target hook.
> > * targhooks.cc (default_have_ccmp): New function.
> > * targhooks.h (default_have_ccmp): New prototype.
> > ---
> > gcc/cfgexpand.cc | 2 +-
> > gcc/config/i386/i386.cc | 9 +++++++++
> > gcc/doc/tm.texi | 6 ++++++
> > gcc/doc/tm.texi.in | 2 ++
> > gcc/expr.cc | 2 +-
> > gcc/target.def | 9 +++++++++
> > gcc/targhooks.cc | 6 ++++++
> > gcc/targhooks.h | 1 +
> > 8 files changed, 35 insertions(+), 2 deletions(-)
> >
> > diff --git a/gcc/cfgexpand.cc b/gcc/cfgexpand.cc
> > index 8de5f2ba58b..dad3ae1b7c6 100644
> > --- a/gcc/cfgexpand.cc
> > +++ b/gcc/cfgexpand.cc
> > @@ -2646,7 +2646,7 @@ expand_gimple_cond (basic_block bb, gcond *stmt)
> > /* If jumps are cheap and the target does not support conditional
> > compare, turn some more codes into jumpy sequences. */
> > else if (BRANCH_COST (optimize_insn_for_speed_p (), false) < 4
> > - && targetm.gen_ccmp_first == NULL)
> > + && !targetm.have_ccmp ())
> > {
> > if ((code2 == BIT_AND_EXPR
> > && TYPE_PRECISION (TREE_TYPE (op0)) == 1
> > diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
> > index 173db213d14..c72f64da983 100644
> > --- a/gcc/config/i386/i386.cc
> > +++ b/gcc/config/i386/i386.cc
> > @@ -26204,6 +26204,13 @@ ix86_memtag_add_tag (rtx base, poly_int64 offset,
> > unsigned char tag_offset)
> > return plus_constant (Pmode, tagged_addr, offset);
> > }
> >
> > +/* Implement TARGET_HAVE_CCMP. */
> > +static bool
> > +ix86_have_ccmp ()
> > +{
> > + return (bool) TARGET_APX_CCMP;
> > +}
> > +
> > /* Target-specific selftests. */
> >
> > #if CHECKING_P
> > @@ -27043,6 +27050,8 @@ ix86_libgcc_floating_mode_supported_p
> > #undef TARGET_GEN_CCMP_NEXT
> > #define TARGET_GEN_CCMP_NEXT ix86_gen_ccmp_next
> >
> > +#undef TARGET_HAVE_CCMP
> > +#define TARGET_HAVE_CCMP ix86_have_ccmp
> >
> > static bool
> > ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
> > diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
> > index 8a7aa70d605..993816deeba 100644
> > --- a/gcc/doc/tm.texi
> > +++ b/gcc/doc/tm.texi
> > @@ -12354,6 +12354,12 @@ This function prepares to emit a conditional
> > comparison within a sequence
> > @var{bit_code} is @code{AND} or @code{IOR}, which is the op on the
> > compares.
> > @end deftypefn
> >
> > +@deftypefn {Target Hook} bool TARGET_HAVE_CCMP (void)
> > +This target hook returns true if the target supports conditional compare.
> > +This target hook is required only when the target has conditional compare
> > that
> > +was not enabled by default, such as x86-64.
>
> Maybe the second sentence could be something like:
>
> -----
> The hook is required only when the support is conditionally enabled,
> such as in response to command-line flags. The default implementation
> returns true iff @code{TARGET_GEN_CCMP_FIRST} is defined.
> -----
>
> The reason for the suggestion is that "was enabled by default" sounds to
> me like it's describing behaviour that can be altered by command-line flags,
> rather than something that happens unconditionally.
>
> OK with that change, thanks.
>
> Richard
>
> > +@end deftypefn
> > +
> > @deftypefn {Target Hook} unsigned TARGET_LOOP_UNROLL_ADJUST (unsigned
> > @var{nunroll}, class loop *@var{loop})
> > This target hook returns a new value for the number of times @var{loop}
> > should be unrolled. The parameter @var{nunroll} is the number of times
> > diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
> > index 9e0830758ae..87a7f895174 100644
> > --- a/gcc/doc/tm.texi.in
> > +++ b/gcc/doc/tm.texi.in
> > @@ -7923,6 +7923,8 @@ lists.
> >
> > @hook TARGET_GEN_CCMP_NEXT
> >
> > +@hook TARGET_HAVE_CCMP
> > +
> > @hook TARGET_LOOP_UNROLL_ADJUST
> >
> > @defmac POWI_MAX_MULTS
> > diff --git a/gcc/expr.cc b/gcc/expr.cc
> > index 1baa39b98eb..04bad5e1425 100644
> > --- a/gcc/expr.cc
> > +++ b/gcc/expr.cc
> > @@ -11089,7 +11089,7 @@ expand_expr_real_gassign (gassign *g, rtx target,
> > machine_mode tmode,
> > ops.op1 = gimple_assign_rhs2 (g);
> >
> > /* Try to expand conditonal compare. */
> > - if (targetm.gen_ccmp_first)
> > + if (targetm.have_ccmp ())
> > {
> > gcc_checking_assert (targetm.gen_ccmp_next != NULL);
> > r = expand_ccmp_expr (g, TYPE_MODE (ops.type));
> > diff --git a/gcc/target.def b/gcc/target.def
> > index 70070caebc7..1511038785d 100644
> > --- a/gcc/target.def
> > +++ b/gcc/target.def
> > @@ -2783,6 +2783,15 @@ DEFHOOK
> > rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, rtx_code
> > cmp_code, tree op0, tree op1, rtx_code bit_code),
> > NULL)
> >
> > +/* Return true if the target supports conditional compare. */
> > +DEFHOOK
> > +(have_ccmp,
> > + "This target hook returns true if the target supports conditional
> > compare.\n\
> > +This target hook is required only when the target has conditional compare
> > that\n\
> > +was not enabled by default, such as x86-64.",
> > + bool, (void),
> > + default_have_ccmp)
> > +
> > /* Return a new value for loop unroll size. */
> > DEFHOOK
> > (loop_unroll_adjust,
> > diff --git a/gcc/targhooks.cc b/gcc/targhooks.cc
> > index fb339bf75dd..4f53257e55c 100644
> > --- a/gcc/targhooks.cc
> > +++ b/gcc/targhooks.cc
> > @@ -1887,6 +1887,12 @@ default_have_conditional_execution (void)
> > return HAVE_conditional_execution;
> > }
> >
> > +bool
> > +default_have_ccmp (void)
> > +{
> > + return targetm.gen_ccmp_first != NULL;
> > +}
> > +
> > /* By default we assume that c99 functions are present at the runtime,
> > but sincos is not. */
> > bool
> > diff --git a/gcc/targhooks.h b/gcc/targhooks.h
> > index 85f3817c176..f53913ebdfa 100644
> > --- a/gcc/targhooks.h
> > +++ b/gcc/targhooks.h
> > @@ -216,6 +216,7 @@ extern void default_addr_space_diagnose_usage
> > (addr_space_t, location_t);
> > extern rtx default_addr_space_convert (rtx, tree, tree);
> > extern unsigned int default_case_values_threshold (void);
> > extern bool default_have_conditional_execution (void);
> > +extern bool default_have_ccmp (void);
> >
> > extern bool default_libc_has_function (enum function_class, tree);
> > extern bool default_libc_has_fast_function (int fcode);
From c9883121f14c34f52769652fd5c6203758b5f780 Mon Sep 17 00:00:00 2001
From: Hongyu Wang <hongyu.w...@intel.com>
Date: Thu, 13 Jun 2024 00:18:32 +0800
Subject: [PATCH] Add targetm.have_ccmp hook
In cfgexpand, there is an optimization for branch which tests
targetm.gen_ccmp_first == NULL. However for target like x86-64, the
hook was implemented but it does not indicate that ccmp was enabled.
Add a new target hook TARGET_HAVE_CCMP and replace the middle-end
check for the existance of gen_ccmp_first to avoid misoptimization.
gcc/ChangeLog:
PR target/115370
PR target/115463
* cfgexpand.cc (expand_gimple_cond): Call targetm.have_ccmp
instead of checking if targetm.gen_ccmp_first exists.
* expr.cc (expand_expr_real_gassign): Likewise.
* config/i386/i386.cc (ix86_have_ccmp): New target hook to
check if APX_CCMP enabled.
(TARGET_HAVE_CCMP): Define.
* doc/tm.texi: Add TARGET_HAVE_CCMP.
* doc/tm.texi.in: Regenerated.
* target.def (TARGET_HAVE_CCMP): New target hook.
* targhooks.cc (default_have_ccmp): New function.
* targhooks.h (default_have_ccmp): New prototype.
---
gcc/cfgexpand.cc | 2 +-
gcc/config/i386/i386.cc | 9 +++++++++
gcc/doc/tm.texi | 7 +++++++
gcc/doc/tm.texi.in | 2 ++
gcc/expr.cc | 2 +-
gcc/target.def | 10 ++++++++++
gcc/targhooks.cc | 6 ++++++
gcc/targhooks.h | 1 +
8 files changed, 37 insertions(+), 2 deletions(-)
diff --git a/gcc/cfgexpand.cc b/gcc/cfgexpand.cc
index 8de5f2ba58b..dad3ae1b7c6 100644
--- a/gcc/cfgexpand.cc
+++ b/gcc/cfgexpand.cc
@@ -2646,7 +2646,7 @@ expand_gimple_cond (basic_block bb, gcond *stmt)
/* If jumps are cheap and the target does not support conditional
compare, turn some more codes into jumpy sequences. */
else if (BRANCH_COST (optimize_insn_for_speed_p (), false) < 4
- && targetm.gen_ccmp_first == NULL)
+ && !targetm.have_ccmp ())
{
if ((code2 == BIT_AND_EXPR
&& TYPE_PRECISION (TREE_TYPE (op0)) == 1
diff --git a/gcc/config/i386/i386.cc b/gcc/config/i386/i386.cc
index 173db213d14..c72f64da983 100644
--- a/gcc/config/i386/i386.cc
+++ b/gcc/config/i386/i386.cc
@@ -26204,6 +26204,13 @@ ix86_memtag_add_tag (rtx base, poly_int64 offset, unsigned char tag_offset)
return plus_constant (Pmode, tagged_addr, offset);
}
+/* Implement TARGET_HAVE_CCMP. */
+static bool
+ix86_have_ccmp ()
+{
+ return (bool) TARGET_APX_CCMP;
+}
+
/* Target-specific selftests. */
#if CHECKING_P
@@ -27043,6 +27050,8 @@ ix86_libgcc_floating_mode_supported_p
#undef TARGET_GEN_CCMP_NEXT
#define TARGET_GEN_CCMP_NEXT ix86_gen_ccmp_next
+#undef TARGET_HAVE_CCMP
+#define TARGET_HAVE_CCMP ix86_have_ccmp
static bool
ix86_libc_has_fast_function (int fcode ATTRIBUTE_UNUSED)
diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi
index 8a7aa70d605..be5543b72f8 100644
--- a/gcc/doc/tm.texi
+++ b/gcc/doc/tm.texi
@@ -12354,6 +12354,13 @@ This function prepares to emit a conditional comparison within a sequence
@var{bit_code} is @code{AND} or @code{IOR}, which is the op on the compares.
@end deftypefn
+@deftypefn {Target Hook} bool TARGET_HAVE_CCMP (void)
+This target hook returns true if the target supports conditional compare.
+This target hook is required only when the ccmp support is conditionally
+enabled, such as in response to command-line flags. The default implementation
+returns true iff @code{TARGET_GEN_CCMP_FIRST} is defined.
+@end deftypefn
+
@deftypefn {Target Hook} unsigned TARGET_LOOP_UNROLL_ADJUST (unsigned @var{nunroll}, class loop *@var{loop})
This target hook returns a new value for the number of times @var{loop}
should be unrolled. The parameter @var{nunroll} is the number of times
diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in
index 9e0830758ae..87a7f895174 100644
--- a/gcc/doc/tm.texi.in
+++ b/gcc/doc/tm.texi.in
@@ -7923,6 +7923,8 @@ lists.
@hook TARGET_GEN_CCMP_NEXT
+@hook TARGET_HAVE_CCMP
+
@hook TARGET_LOOP_UNROLL_ADJUST
@defmac POWI_MAX_MULTS
diff --git a/gcc/expr.cc b/gcc/expr.cc
index 1baa39b98eb..04bad5e1425 100644
--- a/gcc/expr.cc
+++ b/gcc/expr.cc
@@ -11089,7 +11089,7 @@ expand_expr_real_gassign (gassign *g, rtx target, machine_mode tmode,
ops.op1 = gimple_assign_rhs2 (g);
/* Try to expand conditonal compare. */
- if (targetm.gen_ccmp_first)
+ if (targetm.have_ccmp ())
{
gcc_checking_assert (targetm.gen_ccmp_next != NULL);
r = expand_ccmp_expr (g, TYPE_MODE (ops.type));
diff --git a/gcc/target.def b/gcc/target.def
index 70070caebc7..e5a9b52676e 100644
--- a/gcc/target.def
+++ b/gcc/target.def
@@ -2783,6 +2783,16 @@ DEFHOOK
rtx, (rtx_insn **prep_seq, rtx_insn **gen_seq, rtx prev, rtx_code cmp_code, tree op0, tree op1, rtx_code bit_code),
NULL)
+/* Return true if the target supports conditional compare. */
+DEFHOOK
+(have_ccmp,
+ "This target hook returns true if the target supports conditional compare.\n\
+This target hook is required only when the ccmp support is conditionally\n\
+enabled, such as in response to command-line flags. The default implementation\n\
+returns true iff @code{TARGET_GEN_CCMP_FIRST} is defined.",
+ bool, (void),
+ default_have_ccmp)
+
/* Return a new value for loop unroll size. */
DEFHOOK
(loop_unroll_adjust,
diff --git a/gcc/targhooks.cc b/gcc/targhooks.cc
index fb339bf75dd..4f53257e55c 100644
--- a/gcc/targhooks.cc
+++ b/gcc/targhooks.cc
@@ -1887,6 +1887,12 @@ default_have_conditional_execution (void)
return HAVE_conditional_execution;
}
+bool
+default_have_ccmp (void)
+{
+ return targetm.gen_ccmp_first != NULL;
+}
+
/* By default we assume that c99 functions are present at the runtime,
but sincos is not. */
bool
diff --git a/gcc/targhooks.h b/gcc/targhooks.h
index 85f3817c176..f53913ebdfa 100644
--- a/gcc/targhooks.h
+++ b/gcc/targhooks.h
@@ -216,6 +216,7 @@ extern void default_addr_space_diagnose_usage (addr_space_t, location_t);
extern rtx default_addr_space_convert (rtx, tree, tree);
extern unsigned int default_case_values_threshold (void);
extern bool default_have_conditional_execution (void);
+extern bool default_have_ccmp (void);
extern bool default_libc_has_function (enum function_class, tree);
extern bool default_libc_has_fast_function (int fcode);
--
2.31.1
