[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]
Re: [Qemu-devel] [PATCH] target-mips: fix mipsdsp_trunc16_sat16_round
From: |
Petar Jovanovic |
Subject: |
Re: [Qemu-devel] [PATCH] target-mips: fix mipsdsp_trunc16_sat16_round |
Date: |
Mon, 17 Jun 2013 22:39:52 +0000 |
ping
________________________________________
From: Petar Jovanovic
Sent: Sunday, June 09, 2013 4:34 AM
To: Petar Jovanovic; address@hidden
Cc: address@hidden
Subject: RE: [PATCH] target-mips: fix mipsdsp_trunc16_sat16_round
ping
http://patchwork.ozlabs.org/patch/245624/
________________________________________
From: Petar Jovanovic address@hidden
Sent: Wednesday, May 22, 2013 3:35 PM
To: address@hidden
Cc: Petar Jovanovic; address@hidden
Subject: [PATCH] target-mips: fix mipsdsp_trunc16_sat16_round
From: Petar Jovanovic <address@hidden>
This change corrects rounding and saturation of Q31 fractional value in
mipsdsp_trunc16_sat16_round(). Overflow detection was incorrect for the
corner case for PRECRQ_RS.PH, and this test case is also part of the change.
Signed-off-by: Petar Jovanovic <address@hidden>
---
target-mips/dsp_helper.c | 12 ++++++------
tests/tcg/mips/mips32-dsp/precrq_rs_ph_w.c | 24 ++++++++++++++++++++----
2 files changed, 26 insertions(+), 10 deletions(-)
diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
index 4116de9..306b332 100644
--- a/target-mips/dsp_helper.c
+++ b/target-mips/dsp_helper.c
@@ -648,16 +648,16 @@ static inline int32_t mipsdsp_sat16_mul_q15_q15(uint16_t
a, uint16_t b,
static inline uint16_t mipsdsp_trunc16_sat16_round(int32_t a,
CPUMIPSState *env)
{
- int64_t temp;
-
- temp = (int32_t)a + 0x00008000;
+ uint16_t temp;
- if (a > (int)0x7fff8000) {
- temp = 0x7FFFFFFF;
+ if (a > 0x7FFF7FFF) {
+ temp = 0x7FFF;
set_DSPControl_overflow_flag(1, 22, env);
+ } else {
+ temp = ((a + 0x8000) >> 16) & 0xFFFF;
}
- return (temp >> 16) & 0xFFFF;
+ return temp;
}
static inline uint8_t mipsdsp_sat8_reduce_precision(uint16_t a,
diff --git a/tests/tcg/mips/mips32-dsp/precrq_rs_ph_w.c
b/tests/tcg/mips/mips32-dsp/precrq_rs_ph_w.c
index 3535b37..da6845b 100644
--- a/tests/tcg/mips/mips32-dsp/precrq_rs_ph_w.c
+++ b/tests/tcg/mips/mips32-dsp/precrq_rs_ph_w.c
@@ -12,18 +12,34 @@ int main()
result = 0x12348765;
__asm
- ("precrq_rs.ph.w %0, %1, %2\n\t"
+ ("wrdsp $0\n\t"
+ "precrq_rs.ph.w %0, %1, %2\n\t"
: "=r"(rd)
: "r"(rs), "r"(rt)
);
assert(result == rd);
- rs = 0x7fffC678;
+ rs = 0x7FFFC678;
rt = 0x865432A0;
- result = 0x7fff8654;
+ result = 0x7FFF8654;
__asm
- ("precrq_rs.ph.w %0, %2, %3\n\t"
+ ("wrdsp $0\n\t"
+ "precrq_rs.ph.w %0, %2, %3\n\t"
+ "rddsp %1\n\t"
+ : "=r"(rd), "=r"(dsp)
+ : "r"(rs), "r"(rt)
+ );
+ assert(((dsp >> 22) & 0x01) == 1);
+ assert(result == rd);
+
+ rs = 0xBEEFFEED;
+ rt = 0x7FFF8000;
+ result = 0xBEF07FFF;
+
+ __asm
+ ("wrdsp $0\n\t"
+ "precrq_rs.ph.w %0, %2, %3\n\t"
"rddsp %1\n\t"
: "=r"(rd), "=r"(dsp)
: "r"(rs), "r"(rt)
--
1.7.9.5