--- /dev/null
+dnl PowerPC-32 mpn_rshift -- Shift a number right.
+
+dnl Copyright 1995, 1998, 2000, 2002, 2003, 2004, 2005 Free Software
+dnl Foundation, Inc.
+
+dnl This file is part of the GNU MP Library.
+
+dnl The GNU MP Library is free software; you can redistribute it and/or modify
+dnl it under the terms of the GNU Lesser General Public License as published
+dnl by the Free Software Foundation; either version 3 of the License, or (at
+dnl your option) any later version.
+
+dnl The GNU MP Library is distributed in the hope that it will be useful, but
+dnl WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
+dnl or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public
+dnl License for more details.
+
+dnl You should have received a copy of the GNU Lesser General Public License
+dnl along with the GNU MP Library. If not, see http://www.gnu.org/licenses/.
+
+include(`../config.m4')
+
+C cycles/limb
+C 603e: ?
+C 604e: 3.0
+C 75x (G3): 3.0
+C 7400,7410 (G4): 3.0
+C 7445,7455 (G4+): 2.5
+C 7447,7457 (G4+): 2.25
+C power4/ppc970: 2.5
+C power5: 2.5
+
+C INPUT PARAMETERS
+C rp r3
+C up r4
+C n r5
+C cnt r6
+
+ASM_START()
+PROLOGUE(mpn_rshift)
+ cmpwi cr0, r5, 12 C more than 12 limbs?
+ addi r7, r3, -4 C dst-4
+ bgt L(BIG) C branch if more than 12 limbs
+
+ mtctr r5 C copy size into CTR
+ subfic r8, r6, 32
+ lwz r11, 0(r4) C load first s1 limb
+ slw r3, r11, r8 C compute function return value
+ bdz L(end1)
+
+L(oop): lwzu r10, 4(r4)
+ srw r9, r11, r6
+ slw r12, r10, r8
+ or r9, r9, r12
+ stwu r9, 4(r7)
+ bdz L(end2)
+ lwzu r11, 4(r4)
+ srw r9, r10, r6
+ slw r12, r11, r8
+ or r9, r9, r12
+ stwu r9, 4(r7)
+ bdnz L(oop)
+
+L(end1):
+ srw r0, r11, r6
+ stw r0, 4(r7)
+ blr
+L(end2):
+ srw r0, r10, r6
+ stw r0, 4(r7)
+ blr
+
+L(BIG):
+ stmw r24, -32(r1) C save registers we are supposed to preserve
+ lwz r9, 0(r4)
+ subfic r8, r6, 32
+ slw r3, r9, r8 C compute function return value
+ srw r0, r9, r6
+ addi r5, r5, -1
+
+ andi. r10, r5, 3 C count for spill loop
+ beq L(e)
+ mtctr r10
+ lwzu r28, 4(r4)
+ bdz L(xe0)
+
+L(loop0):
+ srw r12, r28, r6
+ slw r24, r28, r8
+ lwzu r28, 4(r4)
+ or r24, r0, r24
+ stwu r24, 4(r7)
+ mr r0, r12
+ bdnz L(loop0) C taken at most once!
+
+L(xe0): srw r12, r28, r6
+ slw r24, r28, r8
+ or r24, r0, r24
+ stwu r24, 4(r7)
+ mr r0, r12
+
+L(e): srwi r5, r5, 2 C count for unrolled loop
+ addi r5, r5, -1
+ mtctr r5
+ lwz r28, 4(r4)
+ lwz r29, 8(r4)
+ lwz r30, 12(r4)
+ lwzu r31, 16(r4)
+
+L(loopU):
+ srw r9, r28, r6
+ slw r24, r28, r8
+ lwz r28, 4(r4)
+ srw r10, r29, r6
+ slw r25, r29, r8
+ lwz r29, 8(r4)
+ srw r11, r30, r6
+ slw r26, r30, r8
+ lwz r30, 12(r4)
+ srw r12, r31, r6
+ slw r27, r31, r8
+ lwzu r31, 16(r4)
+ or r24, r0, r24
+ stw r24, 4(r7)
+ or r25, r9, r25
+ stw r25, 8(r7)
+ or r26, r10, r26
+ stw r26, 12(r7)
+ or r27, r11, r27
+ stwu r27, 16(r7)
+ mr r0, r12
+ bdnz L(loopU)
+
+ srw r9, r28, r6
+ slw r24, r28, r8
+ srw r10, r29, r6
+ slw r25, r29, r8
+ srw r11, r30, r6
+ slw r26, r30, r8
+ srw r12, r31, r6
+ slw r27, r31, r8
+ or r24, r0, r24
+ stw r24, 4(r7)
+ or r25, r9, r25
+ stw r25, 8(r7)
+ or r26, r10, r26
+ stw r26, 12(r7)
+ or r27, r11, r27
+ stw r27, 16(r7)
+
+ stw r12, 20(r7)
+ lmw r24, -32(r1) C restore registers
+ blr
+EPILOGUE(mpn_rshift)
projects / msp430-gcc.git / blobdiff