[PATCH] Add targetm.have_ccmp hook [PR115370]

[Hongyu Wang <hongyu.wang@intel.com>]

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.

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.
+@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);
-- 
2.31.1