62 lines
1.7 KiB
ArmAsm
62 lines
1.7 KiB
ArmAsm
/* libs/opengles/arch-mips/fixed_asm.S
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**
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** Copyright 2012, The Android Open Source Project
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**
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** Licensed under the Apache License, Version 2.0 (the "License");
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** you may not use this file except in compliance with the License.
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** You may obtain a copy of the License at
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**
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** http://www.apache.org/licenses/LICENSE-2.0
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**
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** Unless required by applicable law or agreed to in writing, software
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** distributed under the License is distributed on an "AS IS" BASIS,
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** WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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** See the License for the specific language governing permissions and
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** limitations under the License.
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*/
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.text
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.align
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/*
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* this version rounds-to-nearest and saturates numbers
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* outside the range (but not NaNs).
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*/
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.global gglFloatToFixed
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.ent gglFloatToFixed
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.type gglFloatToFixed, @function
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gglFloatToFixed:
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#if !defined(__mips_soft_float)
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mfc1 $a0,$f12
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#endif
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srl $t0,$a0,31 /* t0 <- sign bit */
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srl $t1,$a0,23
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andi $t1,$t1,0xff /* get the e */
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li $t2,0x8e
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subu $t1,$t2,$t1 /* t1=127+15-e */
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blez $t1,0f /* t1<=0? */
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sll $t2,$a0,8 /* mantissa<<8 */
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lui $t3,0x8000
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or $t2,$t2,$t3 /* add the missing 1 */
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subu $t1,$t1,1
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srl $v0,$t2,$t1
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sltiu $t3,$t1,32 /* t3=1 if t1<32, else t3=0. t1>=32 means the float value is too small. */
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andi $t4,$v0,0x1
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srl $v0,$v0,1 /* scale to 16.16 */
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addu $v0,$v0,$t4 /* round-to-nearest */
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subu $t2,$zero,$v0
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movn $v0,$t2,$t0 /* if negative? */
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or $t1,$a0,$zero /* a0=0? */
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movz $v0,$zero,$t1
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movz $v0,$zero,$t3 /* t3=0 then res=0 */
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jr $ra
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0:
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lui $t1,0x8000
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and $v0,$a0,$t1 /* keep only the sign bit */
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li $t1,0x7fffffff
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movz $v0,$t1,$t0 /* positive, maximum value */
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jr $ra
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.end gglFloatToFixed
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