| Duane Sand | b43722c | 2013-03-27 10:53:14 -0700 | [diff] [blame^] | 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 |