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Diffstat (limited to 'arch/openrisc/lib/ashrdi3.S')
| -rw-r--r-- | arch/openrisc/lib/ashrdi3.S | 59 |
1 files changed, 59 insertions, 0 deletions
diff --git a/arch/openrisc/lib/ashrdi3.S b/arch/openrisc/lib/ashrdi3.S new file mode 100644 index 0000000000..c656d9fb6e --- /dev/null +++ b/arch/openrisc/lib/ashrdi3.S @@ -0,0 +1,59 @@ +/* + * (C) Copyright 2012 - Franck JULLIEN <elec4fun@gmail.com> + * + * Extracted from gcc generated assembly. + * + * Extended precision shifts. + * + * R3/R4 (MSW, LSW) has 64 bit value + * R5 has shift count + * result in R11/R12 + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public License as + * published by the Free Software Foundation; either version 2 of + * the License, or (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * You should have received a copy of the GNU General Public License + * along with this program; if not, write to the Free Software + * Foundation, Inc., 59 Temple Place, Suite 330, Boston, + * MA 02111-1307 USA + */ + + +.globl __ashrdi3 + +__ashrdi3: + l.sfeqi r5,0x0 /* if count = 0, go out */ + l.bf out + + l.addi r6,r0,0x20 /* r6 = 32 */ + l.sub r6,r6,r5 /* r6 = 32 - count */ + l.sfgtsi r6,0x0 /* if count >= 32 */ + l.bnf more_than_32 /* branch to more_than_32 */ + l.nop 0x0 + + + less_than_32: + l.sll r6,r3,r6 /* r6 gets the bits moved from MSW to LSW */ + l.srl r4,r4,r5 /* shift LSW */ + l.sra r5,r3,r5 /* shift MSW to r5 */ + l.or r4,r6,r4 /* LSW gets bits shifted from MSW */ + l.ori r3,r5,0x0 /* r3 = MSW */ + + out: + l.ori r11,r3,0x0 + l.jr r9 + l.ori r12,r4,0x0 + + more_than_32: + l.srai r5,r3,0x1f /* r5 = MSW sign extended */ + l.sub r4,r0,r6 /* r4 = -r6, the number of bits above 32 */ + l.sra r4,r3,r4 /* LSW gets bits shifted from MSB */ + l.j out /* go out */ + l.ori r3,r5,0x0 /* r3 = MSW */ |