From mboxrd@z Thu Jan  1 00:00:00 1970
From: Simon Marchi <simon.marchi@polymtl.ca>
Date: Mon, 04 Sep 2017 22:32:29 +0200
Subject: [OpenRISC] [PATCH v4 2/5] sim: cgen: add MUL2OFSI and MUL1OFSI
 macros (needed for OR1K l.mul[u])
In-Reply-To: <700407e5797b8b9b9f76b2dba026d1b06978987b.1496066478.git.shorne@gmail.com>
References: <cover.1496066478.git.shorne@gmail.com>
 <700407e5797b8b9b9f76b2dba026d1b06978987b.1496066478.git.shorne@gmail.com>
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> --- a/sim/common/cgen-ops.h
> +++ b/sim/common/cgen-ops.h
> @@ -631,6 +631,22 @@ SUBOFQI (QI a, QI b, BI c)
>    return res;
>  }
> 
> +SEMOPS_INLINE BI
> +MUL2OFSI (SI a, SI b)
> +{
> +  DI tmp = MULDI (EXTSIDI(a), EXTSIDI(b));
> +  BI res = tmp < -0x80000000LL || tmp > 0x7fffffffLL;
> +  return res;
> +}
> +
> +SEMOPS_INLINE BI
> +MUL1OFSI (USI a, USI b)
> +{
> +  UDI tmp = MULDI (ZEXTSIDI(a), ZEXTSIDI(b));
> +  BI res = (tmp > 0xFFFFFFFFULL);
> +  return res;
> +}

What are these functions expected to return?  They seem to return 1 when 
the result would overflow 32-bits, but just to be sure.

Simon