Fix ARM NAN fraction bits.

Current ARM soft-float implementation is violating the RTABI
(http://infocenter.arm.com/help/topic/com.arm.doc.ihi0043d/IHI0043D_rtabi.pdf)
Section 4.1.1.1:

When not otherwise specified by IEEE 754, the result on an invalid
operation should be the quiet NaN bit pattern with only the most
significant bit of the significand set, and all other significand bits
zero.

This patch fixes it by setting _FP_NANFRAC_* to zero.

Ran make check test with -mfloat-abi=soft. No regression.

	* sysdeps/arm/soft-fp/sfp-machine.h (_FP_NANFRAC_S, _FP_NANFRAC_D)
	(_FP_NANFRAC_Q): Set to zero.

diff --git a/ChangeLog b/ChangeLog
index af8ada1..98d40f2 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,8 @@
+2014-02-27  Joey Ye  <joey.ye@arm.com>
+
+       * sysdeps/arm/soft-fp/sfp-machine.h (_FP_NANFRAC_S, _FP_NANFRAC_D)
+       (_FP_NANFRAC_Q): Set to zero.
+
 2014-02-27  Siddhesh Poyarekar  <siddhesh@redhat.com>
 
        [BZ #16623]

diff --git a/sysdeps/arm/soft-fp/sfp-machine.h b/sysdeps/arm/soft-fp/sfp-machine.h
index 52a08b5..32697fe 100644 (file)
--- a/sysdeps/arm/soft-fp/sfp-machine.h
+++ b/sysdeps/arm/soft-fp/sfp-machine.h
@@ -21,9 +21,9 @@
 #define _FP_DIV_MEAT_D(R,X,Y)  _FP_DIV_MEAT_2_udiv(D,R,X,Y)
 #define _FP_DIV_MEAT_Q(R,X,Y)  _FP_DIV_MEAT_4_udiv(Q,R,X,Y)
 
-#define _FP_NANFRAC_S          ((_FP_QNANBIT_S << 1) - 1)
-#define _FP_NANFRAC_D          ((_FP_QNANBIT_D << 1) - 1), -1
-#define _FP_NANFRAC_Q          ((_FP_QNANBIT_Q << 1) - 1), -1, -1, -1
+#define _FP_NANFRAC_S          0
+#define _FP_NANFRAC_D          0, 0
+#define _FP_NANFRAC_Q          0, 0, 0, 0
 #define _FP_NANSIGN_S          0
 #define _FP_NANSIGN_D          0
 #define _FP_NANSIGN_Q          0