From: Eric Botcazou <ebotcazou@adacore.com>
Date: Fri, 9 Feb 2018 12:33:40 +0000 (+0000)
Subject: optabs.c (prepare_cmp_insn): Try harder to emit a direct comparison instead of a... 
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=183187053d0222477cff678be5360597a57ccc6f;p=gcc.git

optabs.c (prepare_cmp_insn): Try harder to emit a direct comparison instead of a libcall for UNORDERED.

	* optabs.c (prepare_cmp_insn): Try harder to emit a direct comparison
	instead of a libcall for UNORDERED.

From-SVN: r257525
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index b112b8105c7..858ad9dd9db 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,8 @@
+2018-02-09  Eric Botcazou  <ebotcazou@adacore.com>
+
+	* optabs.c (prepare_cmp_insn): Try harder to emit a direct comparison
+	instead of a libcall for UNORDERED.
+
 2018-02-09  Tamar Christina  <tamar.christina@arm.com>
 
 	PR target/82641
diff --git a/gcc/optabs.c b/gcc/optabs.c
index daac5457223..5f61e4e9521 100644
--- a/gcc/optabs.c
+++ b/gcc/optabs.c
@@ -3935,7 +3935,20 @@ prepare_cmp_insn (rtx x, rtx y, enum rtx_code comparison, rtx size,
   if (methods != OPTAB_LIB_WIDEN)
     goto fail;
 
-  if (!SCALAR_FLOAT_MODE_P (mode))
+  if (SCALAR_FLOAT_MODE_P (mode))
+    {
+      /* Small trick if UNORDERED isn't implemented by the hardware.  */
+      if (comparison == UNORDERED && rtx_equal_p (x, y))
+	{
+	  prepare_cmp_insn (x, y, UNLT, NULL_RTX, unsignedp, OPTAB_WIDEN,
+			    ptest, pmode);
+	  if (*ptest)
+	    return;
+	}
+
+      prepare_float_lib_cmp (x, y, comparison, ptest, pmode);
+    }
+  else
     {
       rtx result;
       machine_mode ret_mode;
@@ -3982,8 +3995,6 @@ prepare_cmp_insn (rtx x, rtx y, enum rtx_code comparison, rtx size,
       prepare_cmp_insn (x, y, comparison, NULL_RTX, unsignedp, methods,
 			ptest, pmode);
     }
-  else
-    prepare_float_lib_cmp (x, y, comparison, ptest, pmode);
 
   return;