1 /* libs/opengles/arch-mips/fixed_asm.S 2 ** 3 ** Copyright 2012, The Android Open Source Project 4 ** 5 ** Licensed under the Apache License, Version 2.0 (the "License"); 6 ** you may not use this file except in compliance with the License. 7 ** You may obtain a copy of the License at 8 ** 9 ** http://www.apache.org/licenses/LICENSE-2.0 10 ** 11 ** Unless required by applicable law or agreed to in writing, software 12 ** distributed under the License is distributed on an "AS IS" BASIS, 13 ** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 14 ** See the License for the specific language governing permissions and 15 ** limitations under the License. 16 */ 17 18 19 .text 20 .align 21 22 /* 23 * this version rounds-to-nearest and saturates numbers 24 * outside the range (but not NaNs). 25 */ 26 27 .global gglFloatToFixed 28 .ent gglFloatToFixed 29 .type gglFloatToFixed, @function 30 gglFloatToFixed: 31 #if !defined(__mips_soft_float) 32 mfc1 $a0,$f12 33 #endif 34 srl $t0,$a0,31 /* t0 <- sign bit */ 35 srl $t1,$a0,23 36 andi $t1,$t1,0xff /* get the e */ 37 li $t2,0x8e 38 subu $t1,$t2,$t1 /* t1=127+15-e */ 39 blez $t1,0f /* t1<=0? */ 40 sll $t2,$a0,8 /* mantissa<<8 */ 41 lui $t3,0x8000 42 or $t2,$t2,$t3 /* add the missing 1 */ 43 subu $t1,$t1,1 44 srl $v0,$t2,$t1 45 sltiu $t3,$t1,32 /* t3=1 if t1<32, else t3=0. t1>=32 means the float value is too small. */ 46 andi $t4,$v0,0x1 47 srl $v0,$v0,1 /* scale to 16.16 */ 48 addu $v0,$v0,$t4 /* round-to-nearest */ 49 subu $t2,$zero,$v0 50 movn $v0,$t2,$t0 /* if negative? */ 51 or $t1,$a0,$zero /* a0=0? */ 52 movz $v0,$zero,$t1 53 movz $v0,$zero,$t3 /* t3=0 then res=0 */ 54 jr $ra 55 0: 56 lui $t1,0x8000 57 and $v0,$a0,$t1 /* keep only the sign bit */ 58 li $t1,0x7fffffff 59 movz $v0,$t1,$t0 /* positive, maximum value */ 60 jr $ra 61 .end gglFloatToFixed 62
