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Hexagon (target/hexagon) properly handle denorm in arch_sf_recip_common

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The arch_sf_recip_common function was calling float32_getexp which
adjusts for denorm, but the we actually need the raw exponent bits.

This function is called from 3 instructions
    sfrecipa
    sffixupn
    sffixupd

Test cases added to tests/tcg/hexagon/fpstuff.c

Signed-off-by: Taylor Simpson <tsimpson@quicinc.com>
Message-Id: <20220210021556.9217-6-tsimpson@quicinc.com>
Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Taylor Simpson 2022-02-09 18:15:49 -08:00
parent 9a65990326
commit 77ccf44453
3 changed files with 49 additions and 7 deletions
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6
target/hexagon/arch.c
View File

@ -1,5 +1,5 @@
/*
* Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
* Copyright(c) 2019-2022 Qualcomm Innovation Center, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -298,8 +298,8 @@ int arch_sf_recip_common(float32 *Rs, float32 *Rt, float32 *Rd, int *adjust,
} else {
PeV = 0x00;
/* Basic checks passed */
n_exp = float32_getexp(RsV);
d_exp = float32_getexp(RtV);
n_exp = float32_getexp_raw(RsV);
d_exp = float32_getexp_raw(RtV);
if ((n_exp - d_exp + SF_BIAS) <= SF_MANTBITS) {
/* Near quotient underflow / inexact Q */
PeV = 0x80;

6
target/hexagon/fma_emu.h
View File

@ -1,5 +1,5 @@
/*
* Copyright(c) 2019-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
* Copyright(c) 2019-2022 Qualcomm Innovation Center, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -24,6 +24,10 @@ static inline bool is_finite(float64 x)
}
int32_t float64_getexp(float64 f64);
static inline uint32_t float32_getexp_raw(float32 f32)
{
return extract32(f32, 23, 8);
}
int32_t float32_getexp(float32 f32);
float32 infinite_float32(uint8_t sign);
float32 internal_fmafx(float32 a, float32 b, float32 c,

44
tests/tcg/hexagon/fpstuff.c
View File

@ -1,5 +1,5 @@
/*
* Copyright(c) 2020-2021 Qualcomm Innovation Center, Inc. All Rights Reserved.
* Copyright(c) 2020-2022 Qualcomm Innovation Center, Inc. All Rights Reserved.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
@ -38,6 +38,8 @@ const int SF_NaN_special = 0x7f800001;
const int SF_ANY = 0x3f800000;
const int SF_HEX_NAN = 0xffffffff;
const int SF_small_neg = 0xab98fba8;
const int SF_denorm = 0x00000001;
const int SF_random = 0x346001d6;
const long long DF_NaN = 0x7ff8000000000000ULL;
const long long DF_ANY = 0x3f80000000000000ULL;
@ -250,10 +252,11 @@ static void check_dfminmax(void)
check_fpstatus(usr, FPINVF);
}
static void check_recip_exception(void)
static void check_sfrecipa(void)
{
int result;
int usr;
int pred;
/*
* Check that sfrecipa doesn't set status bits when
@ -329,6 +332,17 @@ static void check_recip_exception(void)
: "r2", "p0", "usr");
check32(result, 0x3f800000);
check_fpstatus(usr, 0);
/*
* Check that sfrecipa properly handles denorm
*/
asm (CLEAR_FPSTATUS
"%0,p0 = sfrecipa(%2, %3)\n\t"
"%1 = p0\n\t"
: "=r"(result), "=r"(pred) : "r"(SF_denorm), "r"(SF_random)
: "p0", "usr");
check32(result, 0x6a920001);
check32(pred, 0x80);
}
static void check_canonical_NaN(void)
@ -455,6 +469,28 @@ static void check_invsqrta(void)
check32(predval, 0x0);
}
static void check_sffixupn(void)
{
int result;
/* Check that sffixupn properly deals with denorm */
asm volatile("%0 = sffixupn(%1, %2)\n\t"
: "=r"(result)
: "r"(SF_random), "r"(SF_denorm));
check32(result, 0x246001d6);
}
static void check_sffixupd(void)
{
int result;
/* Check that sffixupd properly deals with denorm */
asm volatile("%0 = sffixupd(%1, %2)\n\t"
: "=r"(result)
: "r"(SF_denorm), "r"(SF_random));
check32(result, 0x146001d6);
}
static void check_float2int_convs()
{
int res32;
@ -602,9 +638,11 @@ int main()
check_compare_exception();
check_sfminmax();
check_dfminmax();
check_recip_exception();
check_sfrecipa();
check_canonical_NaN();
check_invsqrta();
check_sffixupn();
check_sffixupd();
check_float2int_convs();
puts(err ? "FAIL" : "PASS");