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target-mips: fix mipsdsp_mul_q15_q15 and tests for MAQ_SA_W_PHL/PHR

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The operands for MAQ_SA_W.PHL/MAQ_SA_W.PHR must in specified format.
Otherwise, the results are unpredictable. Once the operands were corrected
in the tests (part of this change), a bug in mipsdsp_mul_q15_q15 became
visible.

This change corrects the tests for MAQ_SA_W.PHL/MAQ_SA_W.PHR and fixes
sign-related issue in mipsdsp_mul_q15_q15. It also removes unnecessary
comment.

Signed-off-by: Petar Jovanovic <petar.jovanovic@imgtec.com>
This commit is contained in:
Petar Jovanovic 2013-04-15 13:54:07 +02:00 • committed by Aurelien Jarno
parent e3d142d073
commit b1ca31d7ce
3 changed files with 19 additions and 31 deletions
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14
target-mips/dsp_helper.c
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@ -269,18 +269,6 @@ static inline int32_t mipsdsp_sat32_acc_q31(int32_t acc, int32_t a,
temp31 = (temp_sum >> 31) & 0x01;
result = temp_sum & 0xFFFFFFFF;
/* FIXME
This sat function may wrong, because user manual wrote:
temp127..0 ← temp + ( (signA) || a31..0
if ( temp32 ≠ temp31 ) then
if ( temp32 = 0 ) then
temp31..0 ← 0x80000000
else
temp31..0 ← 0x7FFFFFFF
endif
DSPControlouflag:16+acc ← 1
endif
*/
if (temp32 != temp31) {
if (temp32 == 0) {
result = 0x7FFFFFFF;
@ -578,7 +566,7 @@ static inline int32_t mipsdsp_mul_q15_q15(int32_t ac, uint16_t a, uint16_t b,
temp = 0x7FFFFFFF;
set_DSPControl_overflow_flag(1, 16 + ac, env);
} else {
temp = ((uint32_t)a * (uint32_t)b) << 1;
temp = ((int16_t)a * (int16_t)b) << 1;
}
return temp;