Do not raise "inexact" from powerpc64 ceil, floor, trunc (bug 15479).

Continuing fixes for ceil, floor and trunc functions not to raise the
"inexact" exception, this patch fixes the versions used on older
powerpc64 processors.  As was done with the round implementations some
time ago, the save of floating-point state is moved after the first
floating-point operation on the input to ensure that any "invalid"
exception from signaling NaN input is included in the saved state, and
then the whole state gets restored rather than just the rounding mode.

This has no effect on configurations using the power5+ code, since
such processors can do these operations with a single instruction (and
those instructions do not set "inexact", so are correct for TS 18661-1
semantics).

Tested for powerpc64.

	[BZ #15479]
	* sysdeps/powerpc/powerpc64/fpu/s_ceil.S (__ceil): Move save of
	floating-point state after first floating-point operation on
	input.  Restore full floating-point state instead of just rounding
	mode.
	* sysdeps/powerpc/powerpc64/fpu/s_ceilf.S (__ceilf): Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_floor.S (__floor): Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_floorf.S (__floorf): Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_trunc.S (__trunc): Likewise.
	* sysdeps/powerpc/powerpc64/fpu/s_truncf.S (__truncf): Likewise.

7 files changed, 47 insertions, 18 deletions

diff --git a/ChangeLog b/ChangeLog
index 4564571809..89c2a9c0f5 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,6 +1,17 @@
 2016-05-25  Joseph Myers  <joseph@codesourcery.com>
 
 	[BZ #15479]
+	* sysdeps/powerpc/powerpc64/fpu/s_ceil.S (__ceil): Move save of
+	floating-point state after first floating-point operation on
+	input.  Restore full floating-point state instead of just rounding
+	mode.
+	* sysdeps/powerpc/powerpc64/fpu/s_ceilf.S (__ceilf): Likewise.
+	* sysdeps/powerpc/powerpc64/fpu/s_floor.S (__floor): Likewise.
+	* sysdeps/powerpc/powerpc64/fpu/s_floorf.S (__floorf): Likewise.
+	* sysdeps/powerpc/powerpc64/fpu/s_trunc.S (__trunc): Likewise.
+	* sysdeps/powerpc/powerpc64/fpu/s_truncf.S (__truncf): Likewise.
+
+	[BZ #15479]
 	* sysdeps/powerpc/powerpc32/fpu/s_ceil.S (__ceil): Move save of
 	floating-point state after first floating-point operation on
 	input.  Restore full floating-point state instead of just rounding
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_ceil.S b/sysdeps/powerpc/powerpc64/fpu/s_ceil.S
index 77fe0f3c96..d2f96bb628 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_ceil.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_ceil.S
@@ -26,11 +26,12 @@
 
 EALIGN (__ceil, 4, 0)
 	CALL_MCOUNT 0
-	mffs	fp11		/* Save current FPU rounding mode.  */
 	lfd	fp13,.LC0@toc(2)
 	fabs	fp0,fp1
 	fsub	fp12,fp13,fp13	/* generate 0.0  */
 	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO52)  */
+	mffs	fp11		/* Save current FPU rounding mode and
+				   "inexact" state.  */
 	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
 	bnllr-	cr7
 	mtfsfi	7,2		/* Set rounding mode toward +inf.  */
@@ -39,7 +40,8 @@ EALIGN (__ceil, 4, 0)
 	fsub	fp1,fp1,fp13	/* x-= TWO52;  */
 	fabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = 0.0; */
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 .L4:
 	bge-	cr6,.L9		/* if (x < 0.0)  */
@@ -48,7 +50,8 @@ EALIGN (__ceil, 4, 0)
 	fnabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = -0.0; */
 .L9:
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 	END (__ceil)
 
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_ceilf.S b/sysdeps/powerpc/powerpc64/fpu/s_ceilf.S
index 91d4a25ae1..ed944912a9 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_ceilf.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_ceilf.S
@@ -27,11 +27,12 @@
 
 EALIGN (__ceilf, 4, 0)
 	CALL_MCOUNT 0
-	mffs	fp11		/* Save current FPU rounding mode.  */
 	lfs	fp13,.LC0@toc(2)
 	fabs	fp0,fp1
 	fsubs	fp12,fp13,fp13	/* generate 0.0  */
 	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO23)  */
+	mffs	fp11		/* Save current FPU rounding mode and
+				   "inexact" state.  */
 	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
 	bnllr-	cr7
 	mtfsfi	7,2		/* Set rounding mode toward +inf.  */
@@ -40,7 +41,8 @@ EALIGN (__ceilf, 4, 0)
 	fsubs	fp1,fp1,fp13	/* x-= TWO23;  */
 	fabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = 0.0; */
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 .L4:
 	bge-	cr6,.L9		/* if (x < 0.0)  */
@@ -49,7 +51,8 @@ EALIGN (__ceilf, 4, 0)
 	fnabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = -0.0; */
 .L9:
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 	END (__ceilf)
 
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_floor.S b/sysdeps/powerpc/powerpc64/fpu/s_floor.S
index afa08b70c4..a304752423 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_floor.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_floor.S
@@ -26,11 +26,12 @@
 
 EALIGN (__floor, 4, 0)
 	CALL_MCOUNT 0
-	mffs	fp11		/* Save current FPU rounding mode.  */
 	lfd	fp13,.LC0@toc(2)
 	fabs	fp0,fp1
 	fsub	fp12,fp13,fp13	/* generate 0.0  */
 	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO52)  */
+	mffs	fp11		/* Save current FPU rounding mode and
+				   "inexact" state.  */
 	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
 	bnllr-	cr7
 	mtfsfi	7,3		/* Set rounding mode toward -inf.  */
@@ -39,7 +40,8 @@ EALIGN (__floor, 4, 0)
 	fsub	fp1,fp1,fp13	/* x-= TWO52;  */
 	fabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = 0.0; */
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 .L4:
 	bge-	cr6,.L9		/* if (x < 0.0)  */
@@ -48,7 +50,8 @@ EALIGN (__floor, 4, 0)
 	fnabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = -0.0; */
 .L9:
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 	END (__floor)
 
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_floorf.S b/sysdeps/powerpc/powerpc64/fpu/s_floorf.S
index 80080ca0b6..24e76b0568 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_floorf.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_floorf.S
@@ -27,11 +27,12 @@
 
 EALIGN (__floorf, 4, 0)
 	CALL_MCOUNT 0
-	mffs	fp11		/* Save current FPU rounding mode.  */
 	lfs	fp13,.LC0@toc(2)
 	fabs	fp0,fp1
 	fsubs	fp12,fp13,fp13	/* generate 0.0  */
 	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO23)  */
+	mffs	fp11		/* Save current FPU rounding mode and
+				   "inexact" state.  */
 	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
 	bnllr-	cr7
 	mtfsfi	7,3		/* Set rounding mode toward -inf.  */
@@ -40,7 +41,8 @@ EALIGN (__floorf, 4, 0)
 	fsubs	fp1,fp1,fp13	/* x-= TWO23;  */
 	fabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = 0.0; */
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 .L4:
 	bge-	cr6,.L9		/* if (x < 0.0)  */
@@ -49,7 +51,8 @@ EALIGN (__floorf, 4, 0)
 	fnabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = -0.0; */
 .L9:
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 	END (__floorf)
 
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_trunc.S b/sysdeps/powerpc/powerpc64/fpu/s_trunc.S
index 4ad939ebc4..f310c317c3 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_trunc.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_trunc.S
@@ -33,11 +33,12 @@
 
 EALIGN (__trunc, 4, 0)
 	CALL_MCOUNT 0
-	mffs	fp11		/* Save current FPU rounding mode.  */
 	lfd	fp13,.LC0@toc(2)
 	fabs	fp0,fp1
 	fsub	fp12,fp13,fp13	/* generate 0.0  */
 	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO52)  */
+	mffs	fp11		/* Save current FPU rounding mode and
+				   "inexact" state.  */
 	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
 	bnllr-	cr7
 	mtfsfi	7,1		/* Set rounding toward 0 mode.  */
@@ -46,7 +47,8 @@ EALIGN (__trunc, 4, 0)
 	fsub	fp1,fp1,fp13	/* x-= TWO52;  */
 	fabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = 0.0; */
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 .L4:
 	bge-	cr6,.L9		/* if (x < 0.0)  */
@@ -55,7 +57,8 @@ EALIGN (__trunc, 4, 0)
 	fnabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = -0.0; */
 .L9:
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 	END (__trunc)
 
diff --git a/sysdeps/powerpc/powerpc64/fpu/s_truncf.S b/sysdeps/powerpc/powerpc64/fpu/s_truncf.S
index 3a990550d6..b4fce645cd 100644
--- a/sysdeps/powerpc/powerpc64/fpu/s_truncf.S
+++ b/sysdeps/powerpc/powerpc64/fpu/s_truncf.S
@@ -34,11 +34,12 @@
 
 EALIGN (__truncf, 4, 0)
 	CALL_MCOUNT 0
-	mffs	fp11		/* Save current FPU rounding mode.  */
 	lfs	fp13,.LC0@toc(2)
 	fabs	fp0,fp1
 	fsubs	fp12,fp13,fp13	/* generate 0.0  */
 	fcmpu	cr7,fp0,fp13	/* if (fabs(x) > TWO23)  */
+	mffs	fp11		/* Save current FPU rounding mode and
+				   "inexact" state.  */
 	fcmpu	cr6,fp1,fp12	/* if (x > 0.0)  */
 	bnllr-	cr7
 	mtfsfi	7,1		/* Set rounding toward 0 mode.  */
@@ -47,7 +48,8 @@ EALIGN (__truncf, 4, 0)
 	fsubs	fp1,fp1,fp13	/* x-= TWO23;  */
 	fabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = 0.0; */
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 .L4:
 	bge-	cr6,.L9		/* if (x < 0.0)  */
@@ -56,7 +58,8 @@ EALIGN (__truncf, 4, 0)
 	fnabs	fp1,fp1		/* if (x == 0.0)  */
 				/* x = -0.0; */
 .L9:
-	mtfsf	0x01,fp11	/* restore previous rounding mode.  */
+	mtfsf	0xff,fp11	/* Restore previous rounding mode and
+				   "inexact" state.  */
 	blr
 	END (__truncf)