From 1a442c09310de23d7cab4c5efedba607c2672d44 Mon Sep 17 00:00:00 2001 From: Taylor Simpson Date: Mon, 6 Mar 2023 18:58:25 -0800 Subject: Hexagon (target/hexagon) Change subtract from zero to change sign The F2_sffms instruction [r0 -= sfmpy(r1, r2)] doesn't properly handle -0. Previously we would negate the input operand by subtracting from zero. Instead, we negate by changing the sign bit. Test case added to tests/tcg/hexagon/fpstuff.c Signed-off-by: Taylor Simpson Reviewed-by: Anton Johansson Message-Id: <20230307025828.1612809-12-tsimpson@quicinc.com> --- tests/tcg/hexagon/fpstuff.c | 31 ++++++++++++++++++++++++++++++- 1 file changed, 30 insertions(+), 1 deletion(-) (limited to 'tests') diff --git a/tests/tcg/hexagon/fpstuff.c b/tests/tcg/hexagon/fpstuff.c index 56bf562a40..90ce9a6ef3 100644 --- a/tests/tcg/hexagon/fpstuff.c +++ b/tests/tcg/hexagon/fpstuff.c @@ -1,5 +1,5 @@ /* - * Copyright(c) 2020-2022 Qualcomm Innovation Center, Inc. All Rights Reserved. + * Copyright(c) 2020-2023 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 @@ -40,6 +40,7 @@ const int SF_HEX_NAN = 0xffffffff; const int SF_small_neg = 0xab98fba8; const int SF_denorm = 0x00000001; const int SF_random = 0x346001d6; +const int SF_neg_zero = 0x80000000; const long long DF_QNaN = 0x7ff8000000000000ULL; const long long DF_SNaN = 0x7ff7000000000000ULL; @@ -536,6 +537,33 @@ static void check_sffixupd(void) check32(result, 0x146001d6); } +static void check_sffms(void) +{ + int result; + + /* Check that sffms properly deals with -0 */ + result = SF_neg_zero; + asm ("%0 -= sfmpy(%1 , %2)\n\t" + : "+r"(result) + : "r"(SF_ZERO), "r"(SF_ZERO) + : "r12", "r8"); + check32(result, SF_neg_zero); + + result = SF_ZERO; + asm ("%0 -= sfmpy(%1 , %2)\n\t" + : "+r"(result) + : "r"(SF_neg_zero), "r"(SF_ZERO) + : "r12", "r8"); + check32(result, SF_ZERO); + + result = SF_ZERO; + asm ("%0 -= sfmpy(%1 , %2)\n\t" + : "+r"(result) + : "r"(SF_ZERO), "r"(SF_neg_zero) + : "r12", "r8"); + check32(result, SF_ZERO); +} + static void check_float2int_convs() { int res32; @@ -688,6 +716,7 @@ int main() check_invsqrta(); check_sffixupn(); check_sffixupd(); + check_sffms(); check_float2int_convs(); puts(err ? "FAIL" : "PASS"); -- cgit v1.2.3