Patchwork SPARC: fix nearbyint on sNaN input

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Submitter Aurelien Jarno
Date June 30, 2016, 10:35 p.m.
Message ID <1467326157-32579-1-git-send-email-aurelien@aurel32.net>
Download mbox | patch
Permalink /patch/13541/
State New
Headers show

Comments

Aurelien Jarno - June 30, 2016, 10:35 p.m.
nearbyint and nearbyintf should not trigger inexact exceptions, but
should still trigger an invalid exception for a sNaN input.

The SPARC specific implementations of these functions save the FSR at
the beginning of the function and restore it at the end to not trigger
an inexact exception. This however doesn't work for an sNaN input which
need to trigger an invalid exception. Fix that by adding a fcmp
instruction using the input value before saving FSR, so that an invalid
exception is triggered for a sNaN input.

This fixes the math/test-nearbyint-except test on SPARC.

Changelog:
	* sparc/sparc32/sparcv9/fpu/s_nearbyint.S (__nearbyint): Trigger an
	invalid exception for a sNaN input.
	* sparc/sparc32/sparcv9/fpu/s_nearbyintf.S (__nearbyintf): Likewise.
	* sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S
	(__nearbyint_vis3): Likewise
	* sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S
	(__nearbyintf_vis3): Likewise
	* sparc/sparc64/fpu/s_nearbyint.S (__nearbyint): Likewise.
	* sparc/sparc64/fpu/s_nearbyintf.S (__nearbyintf): Likewise.
	* sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S (__nearbyint_vis3):
	Likewise.
	* sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S (__nearbyintf_vis3):
	Likewise.
---
 ChangeLog                                                | 16 ++++++++++++++++
 .../sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S     |  1 +
 .../sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S    |  1 +
 sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyint.S          |  1 +
 sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyintf.S         |  1 +
 sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S   |  1 +
 sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S  |  1 +
 sysdeps/sparc/sparc64/fpu/s_nearbyint.S                  |  1 +
 sysdeps/sparc/sparc64/fpu/s_nearbyintf.S                 |  1 +
 9 files changed, 24 insertions(+)
David Miller - July 1, 2016, 8:39 a.m.
From: Aurelien Jarno <aurelien@aurel32.net>
Date: Fri,  1 Jul 2016 00:35:57 +0200

> nearbyint and nearbyintf should not trigger inexact exceptions, but
> should still trigger an invalid exception for a sNaN input.
> 
> The SPARC specific implementations of these functions save the FSR at
> the beginning of the function and restore it at the end to not trigger
> an inexact exception. This however doesn't work for an sNaN input which
> need to trigger an invalid exception. Fix that by adding a fcmp
> instruction using the input value before saving FSR, so that an invalid
> exception is triggered for a sNaN input.
> 
> This fixes the math/test-nearbyint-except test on SPARC.

Looks good.

Patch

diff --git a/ChangeLog b/ChangeLog
index 497bfe5..170c549 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,21 @@ 
 2016-06-30  Aurelien Jarno  <aurelien@aurel32.net>
 
+	* sparc/sparc32/sparcv9/fpu/s_nearbyint.S (__nearbyint): Trigger an
+	invalid exception for sNaN.
+	* sparc/sparc32/sparcv9/fpu/s_nearbyintf.S (__nearbyintf): Likewise.
+	* sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S
+	(__nearbyint_vis3): Likewise
+	* sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S
+	(__nearbyintf_vis3): Likewise
+	* sparc/sparc64/fpu/s_nearbyint.S (__nearbyint): Likewise.
+	* sparc/sparc64/fpu/s_nearbyintf.S (__nearbyintf): Likewise.
+	* sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S (__nearbyint_vis3):
+	Likewise.
+	* sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S (__nearbyintf_vis3):
+	Likewise
+
+2016-06-30  Aurelien Jarno  <aurelien@aurel32.net>
+
 	* sysdeps/unix/sysv/linux/sparc/sparc64/localplt.data: Add _Qp_cmp.
 
 2016-06-30  Andreas Schwab  <schwab@suse.de>
diff --git a/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S b/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S
index 4475e8c..d9ff0cc 100644
--- a/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S
+++ b/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyint-vis3.S
@@ -36,6 +36,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyint_vis3)
+	fcmpd	%fcc3, %f0, %f0			/* Check for sNaN */
 	st	%fsr, [%sp + 88]
 	sethi	%hi(TWO_FIFTYTWO), %o2
 	sethi	%hi(0xf8003e0), %o5
diff --git a/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S b/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S
index e39134b..5cd1eb0 100644
--- a/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S
+++ b/sysdeps/sparc/sparc32/sparcv9/fpu/multiarch/s_nearbyintf-vis3.S
@@ -35,6 +35,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyintf_vis3)
+	fcmps	%fcc3, %f1, %f1			/* Check for sNaN */
 	st	%fsr, [%sp + 88]
 	movwtos	%o0, %f1
 	sethi	%hi(TWO_TWENTYTHREE), %o2
diff --git a/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyint.S b/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyint.S
index 29b56b4..84a1097 100644
--- a/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyint.S
+++ b/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyint.S
@@ -36,6 +36,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyint)
+	fcmpd	%fcc3, %f0, %f0			/* Check for sNaN */
 	st	%fsr, [%sp + 88]
 	sethi	%hi(TWO_FIFTYTWO), %o2
 	sethi	%hi(0xf8003e0), %o5
diff --git a/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyintf.S b/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyintf.S
index e2188b2..d5cf5ce 100644
--- a/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyintf.S
+++ b/sysdeps/sparc/sparc32/sparcv9/fpu/s_nearbyintf.S
@@ -35,6 +35,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyintf)
+	fcmps	%fcc3, %f1, %f1			/* Check for sNaN */
 	st	%fsr, [%sp + 88]
 	st	%o0, [%sp + 68]
 	sethi	%hi(TWO_TWENTYTHREE), %o2
diff --git a/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S b/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S
index fff277a..3180554 100644
--- a/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S
+++ b/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyint-vis3.S
@@ -35,6 +35,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyint_vis3)
+	fcmpd	%fcc3, %f0, %f0			/* Check for sNaN */
 	stx	%fsr, [%sp + STACK_BIAS + 144]
 	sethi	%hi(TWO_FIFTYTWO), %o2
 	sllx	%o2, 32, %o2
diff --git a/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S b/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S
index c6e94ba..7bf7eed 100644
--- a/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S
+++ b/sysdeps/sparc/sparc64/fpu/multiarch/s_nearbyintf-vis3.S
@@ -35,6 +35,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyintf_vis3)
+	fcmps	%fcc3, %f1, %f1			/* Check for sNaN */
 	stx	%fsr, [%sp + STACK_BIAS + 144]
 	sethi	%hi(0xf8003e0), %o5
 	sethi	%hi(TWO_TWENTYTHREE), %o2
diff --git a/sysdeps/sparc/sparc64/fpu/s_nearbyint.S b/sysdeps/sparc/sparc64/fpu/s_nearbyint.S
index caf4d72..456c315 100644
--- a/sysdeps/sparc/sparc64/fpu/s_nearbyint.S
+++ b/sysdeps/sparc/sparc64/fpu/s_nearbyint.S
@@ -35,6 +35,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyint)
+	fcmpd	%fcc3, %f0, %f0			/* Check for sNaN */
 	stx	%fsr, [%sp + STACK_BIAS + 144]
 	sethi	%hi(TWO_FIFTYTWO), %o2
 	sllx	%o2, 32, %o2
diff --git a/sysdeps/sparc/sparc64/fpu/s_nearbyintf.S b/sysdeps/sparc/sparc64/fpu/s_nearbyintf.S
index 4232eca..d0d9bed 100644
--- a/sysdeps/sparc/sparc64/fpu/s_nearbyintf.S
+++ b/sysdeps/sparc/sparc64/fpu/s_nearbyintf.S
@@ -35,6 +35,7 @@ 
 #define SIGN_BIT	%f12			/* -0.0 */
 
 ENTRY (__nearbyintf)
+	fcmps	%fcc3, %f1, %f1			/* Check for sNaN */
 	stx	%fsr, [%sp + STACK_BIAS + 144]
 	sethi	%hi(0xf8003e0), %o5
 	sethi	%hi(TWO_TWENTYTHREE), %o2