From cc12fd3d8681d3aa29eaa6af9e7f6f9815f721a4 Mon Sep 17 00:00:00 2001
From: Torbjorn Granlund <tg@gmplib.org>
Date: Tue, 2 Nov 2021 01:47:16 +0100
Subject: Rewrite recently added s390_64 sec_tabselect.

---
 mpn/s390_64/sec_tabselect.asm | 113 ++++++++++++++++++++++++++++++------------
 1 file changed, 80 insertions(+), 33 deletions(-)

(limited to 'mpn')

diff --git a/mpn/s390_64/sec_tabselect.asm b/mpn/s390_64/sec_tabselect.asm
index 4bfee09ed..f01cbd780 100644
--- a/mpn/s390_64/sec_tabselect.asm
+++ b/mpn/s390_64/sec_tabselect.asm
@@ -31,14 +31,14 @@ dnl  see https://www.gnu.org/licenses/.
 include(`../config.m4')
 
 C            cycles/limb
-C z900		 ?
+C z900		 -		slfi unsupported
 C z990		 ?
 C z9		 ?
 C z10		 ?
 C z196		 ?
 C z13		 ?
 C z14		 ?
-C z15		 ?
+C z15		 1.6
 
 dnl void
 dnl mpn_sec_tabselect (volatile mp_limb_t *rp, volatile const mp_limb_t *tab,
@@ -48,42 +48,89 @@ define(`rp',	`%r2')
 define(`tp',	`%r3')
 define(`n',	`%r4')
 define(`nents',	`%r5')
-define(`which',	`%r6')
+define(`which_arg',`%r6')	C magicked to stack
 
-ASM_START()
-PROLOGUE(mpn_sec_tabselect)
-	stmg	%r7, %r8, 56(%r15)
-	lgr	%r8, n
-	sllg	n, n, 3
+dnl    r0    r1    r2    r3    r4    r5    r6    r7
+dnl    r8    r9    r10   r11   r12   r13   r14   r15
 
-L(cpy):	lg	%r0, 0(tp)
-	stg	%r0, 0(rp)
-	aghi	tp, 8
-	aghi	rp, 8
-	brctg	%r8, L(cpy)
+define(`mask',	`%r14')
+define(`k',	`%r1')
+define(`which',	`%r0')
 
-	aghi	nents, -1
-	jle	L(ret)
-	slfi	which, 1
-
-L(outer):
-	slfi	which, 1
-	slbgr	%r0, %r0
-	sgr	rp, n
-	srlg	%r8, n, 3
+define(`FRAME', 64)
 
-L(top):	lg	%r1, 0(rp)
-	lg	%r7, 0(tp)
-	xgr	%r7, %r1
-	ngr	%r7, %r0
-	xgr	%r1, %r7
-	stg	%r1, 0(rp)
-	aghi	tp, 8
-	aghi	rp, 8
-	brctg	%r8, L(top)
+ASM_START()
+PROLOGUE(mpn_sec_tabselect)
+	stmg	%r5, %r15, 40(%r15)
+	aghi	%r15, -FRAME
 
-	brctg	nents, L(outer)
+	sllg	n, n, 3
+	msgr	%r5, n
+	stg	%r5, 16(%r15)			C nents * n * LIMB_BYTES
 
-L(ret):	lmg	%r7, %r8, 56(%r15)
+	srlg	%r5, n, 2+3
+	ngr	%r5, %r5
+	je	L(end4)
+L(outer):
+	lg	which, eval(48+FRAME)(%r15)
+	lg	k, eval(40+FRAME)(%r15)		C nents
+	lghi	%r6, 0
+	lghi	%r7, 0
+	lghi	%r8, 0
+	lghi	%r9, 0
+L(tp4):	slfi	which, 1
+	slbgr	mask, mask
+	lmg	%r10, %r13, 0(tp)
+	ngr	%r10, mask
+	ngr	%r11, mask
+	ngr	%r12, mask
+	ngr	%r13, mask
+	agr	%r6, %r10
+	agr	%r7, %r11
+	agr	%r8, %r12
+	agr	%r9, %r13
+	agr	tp, n
+	brctg	k, L(tp4)
+	stmg	%r6, %r9, 0(rp)
+	aghi	rp, 32
+	slg	tp, 16(%r15)
+	aghi	tp, eval(4*8)
+	brctg	%r5, L(outer)
+L(end4):
+	tmll	n, 16
+	je	L(end2)
+	lg	which, eval(48+FRAME)(%r15)
+	lg	k, eval(40+FRAME)(%r15)		C nents
+	lghi	%r6, 0
+	lghi	%r7, 0
+L(tp2):	slfi	which, 1
+	slbgr	mask, mask
+	lmg	%r10, %r11, 0(tp)
+	ngr	%r10, mask
+	ngr	%r11, mask
+	agr	%r6, %r10
+	agr	%r7, %r11
+	agr	tp, n
+	brctg	k, L(tp2)
+	stmg	%r6, %r7, 0(rp)
+	aghi	rp, 16
+	slg	tp, 16(%r15)
+	aghi	tp, eval(2*8)
+L(end2):
+	tmll	n, 8
+	je	L(end1)
+	lg	which, eval(48+FRAME)(%r15)
+	lg	k, eval(40+FRAME)(%r15)		C nents
+	lghi	%r6, 0
+L(tp1):	slfi	which, 1
+	slbgr	mask, mask
+	lg	%r10, 0(tp)
+	ngr	%r10, mask
+	agr	%r6, %r10
+	agr	tp, n
+	brctg	k, L(tp1)
+	stg	%r6, 0(rp)
+L(end1):
+	lmg	%r5, %r15, eval(40+FRAME)(%r15)
 	br	%r14
 EPILOGUE()
-- 
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