* libgcc2.c (__floatdisf, __floatdidf): Don't use IBM Extended

[pf3gnuchains/gcc-fork.git] / gcc / libgcc2.c

diff --git a/gcc/libgcc2.c b/gcc/libgcc2.c
index 03cc448..97717a4 100644 (file)
--- a/gcc/libgcc2.c
+++ b/gcc/libgcc2.c
@@ -1371,7 +1371,14 @@ __floatunditf (UDWtype u)
 #if (defined(L_floatdisf) && LIBGCC2_HAS_SF_MODE)      \
      || (defined(L_floatdidf) && LIBGCC2_HAS_DF_MODE)
 #define DI_SIZE (W_TYPE_SIZE * 2)
-#define F_MODE_OK(SIZE) (SIZE < DI_SIZE && SIZE > (DI_SIZE - SIZE + FSSIZE))
+#define F_MODE_OK(SIZE) \
+  (SIZE < DI_SIZE                                                      \
+   && SIZE > (DI_SIZE - SIZE + FSSIZE)                                 \
+   /* Don't use IBM Extended Double TFmode for TI->SF calculations.    \
+      The conversion from long double to float suffers from double     \
+      rounding, because we convert via double.  In any case, the       \
+      fallback code is faster.  */                                     \
+   && !IS_IBM_EXTENDED (SIZE))
 #if defined(L_floatdisf)
 #define FUNC __floatdisf
 #define FSTYPE SFtype
@@ -1476,7 +1483,14 @@ FUNC (DWtype u)
 #if (defined(L_floatundisf) && LIBGCC2_HAS_SF_MODE)    \
      || (defined(L_floatundidf) && LIBGCC2_HAS_DF_MODE)
 #define DI_SIZE (W_TYPE_SIZE * 2)
-#define F_MODE_OK(SIZE) (SIZE < DI_SIZE && SIZE > (DI_SIZE - SIZE + FSSIZE))
+#define F_MODE_OK(SIZE) \
+  (SIZE < DI_SIZE                                                      \
+   && SIZE > (DI_SIZE - SIZE + FSSIZE)                                 \
+   /* Don't use IBM Extended Double TFmode for TI->SF calculations.    \
+      The conversion from long double to float suffers from double     \
+      rounding, because we convert via double.  In any case, the       \
+      fallback code is faster.  */                                     \
+   && !IS_IBM_EXTENDED (SIZE))
 #if defined(L_floatundisf)
 #define FUNC __floatundisf
 #define FSTYPE SFtype