diff options
Diffstat (limited to 'gcc/config/riscv/riscv-vect-permconst.cc')
| -rw-r--r-- | gcc/config/riscv/riscv-vect-permconst.cc | 20 |
1 files changed, 19 insertions, 1 deletions
diff --git a/gcc/config/riscv/riscv-vect-permconst.cc b/gcc/config/riscv/riscv-vect-permconst.cc index feecc7e..8e13cf8 100644 --- a/gcc/config/riscv/riscv-vect-permconst.cc +++ b/gcc/config/riscv/riscv-vect-permconst.cc @@ -203,6 +203,24 @@ vector_permconst::process_bb (basic_block bb) if (bias < 0 || bias > 16384 / 8) continue; + /* We need to verify that each element would be a valid value + in the inner mode after applying the bias. */ + machine_mode inner = GET_MODE_INNER (GET_MODE (cvec)); + HOST_WIDE_INT precision = GET_MODE_PRECISION (inner).to_constant (); + int i; + for (i = 0; i < CONST_VECTOR_NUNITS (cvec).to_constant (); i++) + { + HOST_WIDE_INT val = INTVAL (CONST_VECTOR_ELT (cvec, i)) - bias; + if (val != sext_hwi (val, precision)) + break; + } + + /* If the loop terminated early, then we found a case where the + adjusted constant would not fit, so we can't record the constant + for this case (it's unlikely to be useful anyway. */ + if (i != CONST_VECTOR_NUNITS (cvec).to_constant ()) + continue; + /* At this point we have a load of a constant integer vector from the constant pool. That constant integer vector is hopefully a permutation constant. We need to make a copy of the vector and @@ -211,7 +229,7 @@ vector_permconst::process_bb (basic_block bb) XXX This violates structure sharing conventions. */ rtvec_def *nvec = gen_rtvec (CONST_VECTOR_NUNITS (cvec).to_constant ()); - for (int i = 0; i < CONST_VECTOR_NUNITS (cvec).to_constant (); i++) + for (i = 0; i < CONST_VECTOR_NUNITS (cvec).to_constant (); i++) nvec->elem[i] = GEN_INT (INTVAL (CONST_VECTOR_ELT (cvec, i)) - bias); rtx copy = gen_rtx_CONST_VECTOR (GET_MODE (cvec), nvec); |