From ef1e3836710e20fb399a72bda0bde0ba7a616078 Mon Sep 17 00:00:00 2001
From: Uros Bizjak <uros@gcc.gnu.org>
Date: Sun, 22 Oct 2017 21:04:36 +0200
Subject: [PATCH] re PR target/52451 (gcc w/i387 float generates fucom rather
 than fcom for floating point comparsons)

	PR target/52451
	* config/i386/i386.c (ix86_fp_compare_mode): Return CCFPmode
	for ordered inequality comparisons even with TARGET_IEEE_FP.

testsuite/ChangeLog:

	PR target/52451
	* gcc.dg/torture/pr52451.c: New test.

From-SVN: r253986
---
 gcc/ChangeLog                          | 13 ++++++++
 gcc/config/i386/i386.c                 | 37 ++++++++++++++++++-----
 gcc/testsuite/ChangeLog                |  8 +++--
 gcc/testsuite/gcc.dg/torture/pr52451.c | 55 ++++++++++++++++++++++++++++++++++
 4 files changed, 103 insertions(+), 10 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr52451.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 3ada30e..78cd3ce 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,16 @@
+2017-10-22  Uros Bizjak  <ubizjak@gmail.com>
+
+	PR target/52451
+	* config/i386/i386.c (ix86_fp_compare_mode): Return CCFPmode
+	for ordered inequality comparisons even with TARGET_IEEE_FP.
+
+2017-10-22  Uros Bizjak  <ubizjak@gmail.com>
+
+	PR target/82628
+	* config/i386/i386.md (cmp<dwi>_doubleword): New pattern.
+	* config/i386/i386.c (ix86_expand_branch) <case E_TImode>:
+	Expand with cmp<dwi>_doubleword.
+
 2017-10-21  Igor Tsimbalist  <igor.v.tsimbalist@intel.com>
 
 	* extend.texi: Add x86 specific to 'nocf_check' attribute.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 5abd4d8..ff0f6f8 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -21682,14 +21682,35 @@ ix86_expand_int_compare (enum rtx_code code, rtx op0, rtx op1)
    Return the appropriate mode to use.  */
 
 machine_mode
-ix86_fp_compare_mode (enum rtx_code)
-{
-  /* ??? In order to make all comparisons reversible, we do all comparisons
-     non-trapping when compiling for IEEE.  Once gcc is able to distinguish
-     all forms trapping and nontrapping comparisons, we can make inequality
-     comparisons trapping again, since it results in better code when using
-     FCOM based compares.  */
-  return TARGET_IEEE_FP ? CCFPUmode : CCFPmode;
+ix86_fp_compare_mode (enum rtx_code code)
+{
+  if (!TARGET_IEEE_FP)
+    return CCFPmode;
+
+  switch (code)
+    {
+    case GT:
+    case GE:
+    case LT:
+    case LE:
+      return CCFPmode;
+
+    case EQ:
+    case NE:
+
+    case LTGT:
+    case UNORDERED:
+    case ORDERED:
+    case UNLT:
+    case UNLE:
+    case UNGT:
+    case UNGE:
+    case UNEQ:
+      return CCFPUmode;
+
+    default:
+      gcc_unreachable ();
+    }
 }
 
 machine_mode
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 493b361..f14930b 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,4 +1,9 @@
 2017-10-22  Uros Bizjak  <ubizjak@gmail.com>
+
+	PR target/52451
+	* gcc.dg/torture/pr52451.c: New test.
+
+2017-10-22  Uros Bizjak  <ubizjak@gmail.com>
 	    Jakub Jelinek  <jakub@redhat.com>
 
 	PR target/82628
@@ -53,8 +58,7 @@
 	* gcc.target/i386/cet-sjlj-3.c: Likewise.
 	* gcc.target/i386/cet-switch-1.c: Likewise.
 	* gcc.target/i386/cet-switch-2.c: Likewise.
-	* lib/target-supports.exp (check_effective_target_cet): New
-	proc.
+	* lib/target-supports.exp (check_effective_target_cet): New proc.
 
 2017-10-20  Jan Hubicka  <hubicka@ucw.cz>
 
diff --git a/gcc/testsuite/gcc.dg/torture/pr52451.c b/gcc/testsuite/gcc.dg/torture/pr52451.c
new file mode 100644
index 0000000..81a3d4d
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr52451.c
@@ -0,0 +1,55 @@
+/* { dg-do run } */
+/* { dg-add-options ieee } */
+/* { dg-require-effective-target fenv_exceptions } */
+
+#include <fenv.h>
+
+#define TEST_C_NOEX(CMP, S)			\
+  r = nan##S CMP arg##S;			\
+  if (fetestexcept (FE_INVALID))		\
+    __builtin_abort ()
+
+#define TEST_B_NOEX(FN, S)			\
+  r = __builtin_##FN (nan##S, arg##S);		\
+  if (fetestexcept (FE_INVALID))		\
+    __builtin_abort ()
+
+#define TEST_C_EX(CMP, S)			\
+  r = nan##S CMP arg##S;			\
+  if (!fetestexcept (FE_INVALID))		\
+    __builtin_abort ();				\
+  feclearexcept (FE_INVALID)
+
+#define TEST(TYPE, S)				\
+  volatile TYPE nan##S = __builtin_nan##S ("");	\
+  volatile TYPE arg##S = 1.0##S;		\
+						\
+  TEST_C_NOEX (==, S);				\
+  TEST_C_NOEX (!=, S);				\
+						\
+  TEST_B_NOEX (isgreater, S);			\
+  TEST_B_NOEX (isless, S);			\
+  TEST_B_NOEX (isgreaterequal, S);		\
+  TEST_B_NOEX (islessequal, S);			\
+						\
+  TEST_B_NOEX (islessgreater, S);		\
+  TEST_B_NOEX (isunordered, S);			\
+						\
+  TEST_C_EX (>, S);				\
+  TEST_C_EX (<, S);				\
+  TEST_C_EX (>=, S);				\
+  TEST_C_EX (<=, S)
+
+int
+main (void)
+{
+  volatile int r;
+
+  feclearexcept (FE_INVALID);
+
+  TEST (float, f);
+  TEST (double, );
+  TEST (long double, l);
+  
+  return 0;
+}
-- 
2.7.4