LLVMValueRef gen_shr(compile_t* c, ast_t* left, ast_t* right)
{
ast_t* type = ast_type(left);
bool sign = is_signed(c->opt, type);
LLVMValueRef l_value = gen_expr(c, left);
LLVMValueRef r_value = gen_expr(c, right);
if((l_value == NULL) || (r_value == NULL))
return NULL;
if(LLVMIsConstant(l_value) && LLVMIsConstant(r_value))
{
if(sign)
return LLVMConstAShr(l_value, r_value);
return LLVMConstLShr(l_value, r_value);
}
if(sign)
return LLVMBuildAShr(c->builder, l_value, r_value, "");
return LLVMBuildLShr(c->builder, l_value, r_value, "");
}
/**
* Generate a * b
*/
LLVMValueRef
lp_build_mul(struct lp_build_context *bld,
LLVMValueRef a,
LLVMValueRef b)
{
const struct lp_type type = bld->type;
LLVMValueRef shift;
LLVMValueRef res;
if(a == bld->zero)
return bld->zero;
if(a == bld->one)
return b;
if(b == bld->zero)
return bld->zero;
if(b == bld->one)
return a;
if(a == bld->undef || b == bld->undef)
return bld->undef;
if(!type.floating && !type.fixed && type.norm) {
if(type.width == 8) {
struct lp_type i16_type = lp_wider_type(type);
LLVMValueRef al, ah, bl, bh, abl, abh, ab;
lp_build_unpack2(bld->builder, type, i16_type, a, &al, &ah);
lp_build_unpack2(bld->builder, type, i16_type, b, &bl, &bh);
/* PMULLW, PSRLW, PADDW */
abl = lp_build_mul_u8n(bld->builder, i16_type, al, bl);
abh = lp_build_mul_u8n(bld->builder, i16_type, ah, bh);
ab = lp_build_pack2(bld->builder, i16_type, type, abl, abh);
return ab;
}
/* FIXME */
assert(0);
}
if(type.fixed)
shift = lp_build_int_const_scalar(type, type.width/2);
else
shift = NULL;
if(LLVMIsConstant(a) && LLVMIsConstant(b)) {
res = LLVMConstMul(a, b);
if(shift) {
if(type.sign)
res = LLVMConstAShr(res, shift);
else
res = LLVMConstLShr(res, shift);
}
}
else {
res = LLVMBuildMul(bld->builder, a, b, "");
if(shift) {
if(type.sign)
res = LLVMBuildAShr(bld->builder, res, shift, "");
else
res = LLVMBuildLShr(bld->builder, res, shift, "");
}
}
return res;
}
