From: Petar Jovanovic <pet...@mips.com>
helper_shilo has not been shifting an accumulator value correctly for negative
values in 'shift' field. Minor optimization for shift=0 case.
This change also adds tests that will trigger issue and check for regressions.
Signed-off-by: Petar Jovanovic <pet...@mips.com>
---
target-mips/dsp_helper.c | 17 +++++++++--------
tests/tcg/mips/mips32-dsp/shilo.c | 18 ++++++++++++++++++
tests/tcg/mips/mips32-dsp/shilov.c | 20 ++++++++++++++++++++
3 files changed, 47 insertions(+), 8 deletions(-)
diff --git a/target-mips/dsp_helper.c b/target-mips/dsp_helper.c
index e7949c2..44f6dc7 100644
--- a/target-mips/dsp_helper.c
+++ b/target-mips/dsp_helper.c
@@ -3814,17 +3814,18 @@ void helper_shilo(target_ulong ac, target_ulong rs,
CPUMIPSState *env)
rs5_0 = rs & 0x3F;
rs5_0 = (int8_t)(rs5_0 << 2) >> 2;
- rs5_0 = MIPSDSP_ABS(rs5_0);
+
+ if (unlikely(rs5_0 == 0)) {
+ return;
+ }
+
acc = (((uint64_t)env->active_tc.HI[ac] << 32) & MIPSDSP_LHI) |
((uint64_t)env->active_tc.LO[ac] & MIPSDSP_LLO);
- if (rs5_0 == 0) {
- temp = acc;
+
+ if (rs5_0 > 0) {
+ temp = acc >> rs5_0;
} else {
- if (rs5_0 > 0) {
- temp = acc >> rs5_0;
- } else {
- temp = acc << rs5_0;
- }
+ temp = acc << -rs5_0;
}
env->active_tc.HI[ac] = (target_ulong)(int32_t)((temp & MIPSDSP_LHI) >>
32);
diff --git a/tests/tcg/mips/mips32-dsp/shilo.c
b/tests/tcg/mips/mips32-dsp/shilo.c
index b686616..ce8ebc6 100644
--- a/tests/tcg/mips/mips32-dsp/shilo.c
+++ b/tests/tcg/mips/mips32-dsp/shilo.c
@@ -23,5 +23,23 @@ int main()
assert(ach == resulth);
assert(acl == resultl);
+
+ ach = 0x1;
+ acl = 0x80000000;
+
+ resulth = 0x3;
+ resultl = 0x0;
+
+ __asm
+ ("mthi %0, $ac1\n\t"
+ "mtlo %1, $ac1\n\t"
+ "shilo $ac1, -1\n\t"
+ "mfhi %0, $ac1\n\t"
+ "mflo %1, $ac1\n\t"
+ : "+r"(ach), "+r"(acl)
+ );
+ assert(ach == resulth);
+ assert(acl == resultl);
+
return 0;
}
diff --git a/tests/tcg/mips/mips32-dsp/shilov.c
b/tests/tcg/mips/mips32-dsp/shilov.c
index f186032..e1d6cea 100644
--- a/tests/tcg/mips/mips32-dsp/shilov.c
+++ b/tests/tcg/mips/mips32-dsp/shilov.c
@@ -25,5 +25,25 @@ int main()
assert(ach == resulth);
assert(acl == resultl);
+
+ rs = 0xffffffff;
+ ach = 0x1;
+ acl = 0x80000000;
+
+ resulth = 0x3;
+ resultl = 0x0;
+
+ __asm
+ ("mthi %0, $ac1\n\t"
+ "mtlo %1, $ac1\n\t"
+ "shilov $ac1, %2\n\t"
+ "mfhi %0, $ac1\n\t"
+ "mflo %1, $ac1\n\t"
+ : "+r"(ach), "+r"(acl)
+ : "r"(rs)
+ );
+ assert(ach == resulth);
+ assert(acl == resultl);
+
return 0;
}
--
1.7.5.4
