Replace div(x) by min(div(x), FLT_MAX)) to avoid getting a NaN result
when x is 0.
A cheaper alternative would be to use legacy mult instructions but they're
not exposed by LLVM.
Cc: mesa-stable
Reviewed-by: Marek Olšák <marek.olsak@amd.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6259>
result = emit_intrin_1f_param(&ctx->ac, "llvm.amdgcn.rcp",
ac_to_float_type(&ctx->ac, def_type), src[0]);
}
result = emit_intrin_1f_param(&ctx->ac, "llvm.amdgcn.rcp",
ac_to_float_type(&ctx->ac, def_type), src[0]);
}
+ if (ctx->abi->clamp_div_by_zero)
+ result = ac_build_fmin(&ctx->ac, result,
+ LLVMConstReal(ac_to_float_type(&ctx->ac, def_type), FLT_MAX));
break;
case nir_op_iand:
result = LLVMBuildAnd(ctx->ac.builder, src[0], src[1], "");
break;
case nir_op_iand:
result = LLVMBuildAnd(ctx->ac.builder, src[0], src[1], "");
case nir_op_frsq:
result = emit_intrin_1f_param(&ctx->ac, "llvm.amdgcn.rsq",
ac_to_float_type(&ctx->ac, def_type), src[0]);
case nir_op_frsq:
result = emit_intrin_1f_param(&ctx->ac, "llvm.amdgcn.rsq",
ac_to_float_type(&ctx->ac, def_type), src[0]);
+ if (ctx->abi->clamp_div_by_zero)
+ result = ac_build_fmin(&ctx->ac, result,
+ LLVMConstReal(ac_to_float_type(&ctx->ac, def_type), FLT_MAX));
break;
case nir_op_frexp_exp:
src[0] = ac_to_float(&ctx->ac, src[0]);
break;
case nir_op_frexp_exp:
src[0] = ac_to_float(&ctx->ac, src[0]);
case nir_op_ffma:
/* FMA is better on GFX10, because it has FMA units instead of MUL-ADD units. */
result = emit_intrin_3f_param(&ctx->ac, ctx->ac.chip_class >= GFX10 ? "llvm.fma" : "llvm.fmuladd",
case nir_op_ffma:
/* FMA is better on GFX10, because it has FMA units instead of MUL-ADD units. */
result = emit_intrin_3f_param(&ctx->ac, ctx->ac.chip_class >= GFX10 ? "llvm.fma" : "llvm.fmuladd",
- ac_to_float_type(&ctx->ac, def_type), src[0], src[1], src[2]);
+ ac_to_float_type(&ctx->ac, def_type), src[0], src[1], src[2]);
break;
case nir_op_ldexp:
src[0] = ac_to_float(&ctx->ac, src[0]);
break;
case nir_op_ldexp:
src[0] = ac_to_float(&ctx->ac, src[0]);
/* Whether undef values must be converted to zero */
bool convert_undef_to_zero;
/* Whether undef values must be converted to zero */
bool convert_undef_to_zero;
+
+ /* Clamp div by 0 (so it won't produce NaN) */
+ bool clamp_div_by_zero;
};
#endif /* AC_SHADER_ABI_H */
};
#endif /* AC_SHADER_ABI_H */