[PATCH, alpha]: Fix sysdeps/alpha/remqu.S clobbering $f3 reg

[Uros Bizjak]

Hello!

Attached patch fixes sysdeps/alpha/remqu.S clobbering $f3 register via
$y_is_neg path. There was missing restore of $f3 before the return
from the function.

The patch also reorders insns a bit, so it becomes similar as much as
possible to divqu.S.

Without the patch, math/big testcase from Go-1.11 testsuite (that
includes lots of corner cases that exercise remqu) FAIL, with patched
function, the testcase PASSes without problems.

Signed-off-by: Uros Bizjak <ubizjak@gmail.com>

Uros.
-------------- next part --------------
diff --git a/sysdeps/alpha/remqu.S b/sysdeps/alpha/remqu.S
index c2c5caf3c20..7210628f973 100644
--- a/sysdeps/alpha/remqu.S
+++ b/sysdeps/alpha/remqu.S
@@ -59,20 +59,19 @@ __remqu:
 	subq	Y, 1, AT
 	stt	$f0, 0(sp)
 	and	Y, AT, AT
+	excb
+	beq	AT, $powerof2
 
 	stt	$f1, 8(sp)
-	excb
 	stt	$f3, 48(sp)
-	beq	AT, $powerof2
 	cfi_rel_offset ($f0, 0)
 	cfi_rel_offset ($f1, 8)
 	cfi_rel_offset ($f3, 48)
+	mf_fpcr	$f3
 
 	_ITOFT2	X, $f0, 16, Y, $f1, 24
-	mf_fpcr	$f3
 	cvtqt	$f0, $f0
 	cvtqt	$f1, $f1
-
 	blt	X, $x_is_neg
 	divt/c	$f0, $f1, $f0
 
@@ -94,12 +93,12 @@ __remqu:
 	mulq	AT, Y, AT
 	ldt	$f0, 0(sp)
 	ldt	$f3, 48(sp)
-	lda	sp, FRAME(sp)
 	cfi_remember_state
 	cfi_restore ($f0)
 	cfi_restore ($f1)
 	cfi_restore ($f3)
 	cfi_def_cfa_offset (0)
+	lda	sp, FRAME(sp)
 
 	.align	4
 	subq	X, AT, RV
@@ -116,11 +115,13 @@ $x_is_neg:
 	cfi_rel_offset ($f2, 24)
 	_ITOFS	AT, $f2, 16
 
+	.align	4
 	addt	$f0, $f2, $f0
+	unop
 	divt/c	$f0, $f1, $f0
+	unop
 
 	/* Ok, we've now the divide issued.  Continue with other checks.  */
-	.align	4
 	ldt	$f1, 8(sp)
 	unop
 	ldt	$f2, 24(sp)
@@ -246,12 +247,16 @@ $y_is_neg:
 	   quotient must be either 0 or 1, so the remainder must be X
 	   or X-Y, so just compute it directly.  */
 	cmpule	Y, X, AT
+	excb
+	mt_fpcr	$f3
 	subq	X, Y, RV
 	ldt	$f0, 0(sp)
+	ldt	$f3, 48(sp)
 	cmoveq	AT, X, RV
 
 	lda	sp, FRAME(sp)
 	cfi_restore ($f0)
+	cfi_restore ($f3)
 	cfi_def_cfa_offset (0)
 	ret	$31, (RA), 1