On 11 February 2011 15:11, <christophe.l...@st.com> wrote: > --- a/target-arm/neon_helper.c > +++ b/target-arm/neon_helper.c > @@ -903,7 +903,7 @@ uint64_t HELPER(neon_qrshl_u64)(CPUState *env, uint64_t > val, uint64_t shiftop) > dest = src1 << tmp; \ > if ((dest >> tmp) != src1) { \ > SET_QC(); \ > - dest = src1 >> 31; \ > + dest = (uint32_t)(1 << (sizeof(src1) * 8 - 1)) - (src1 > 0 ? 1 : > 0); \ > } \ > }} while (0)
This gives the right values but is a pretty long expression (among other things it is more than 80 chars and breaks the QEMU coding style). I'd rather do the same as the existing qshl_s* helper: dest = (uint32_t)(1 << (sizeof(src1) * 8 - 1)); \ if (src1 > 0) { \ dest--; \ } \ > NEON_VOP_ENV(qrshl_s8, neon_s8, 4) > @@ -924,7 +924,11 @@ uint32_t HELPER(neon_qrshl_s32)(CPUState *env, uint32_t > valop, uint32_t shiftop) > dest = val << shift; > if ((dest >> shift) != val) { > SET_QC(); > - dest = (uint32_t)(1 << (sizeof(val) * 8 - 1)) - (val > 0 ? 1 : > 0); > + if (val < 0) { > + dest = INT32_MIN; > + } else { > + dest = INT32_MAX; > + } Again, right answers but the way most of the rest of the code forces a 32 bit value to signed saturation is dest = (val >> 31) ^ ~SIGNBIT; -- PMM