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bh=N/wjUl3m9r8YPv43a4ONQjZjOlKS4ioJdW6M+fE0u9c=; b=YwgtY0E98ouV9J526lj9yN5rlRCi7K7rkbv53glSHCuuNt/0BShk5xpdu5ZhXLmXGssPlp jPjAi/M3XutFw0EwbjXccRP+WaSOvawX4gE6w2N4CLxejwLeWQXWVmEwMMcT+VyiP231Cm 4gPHCoTLujQPonydUhUagVHTputl9Og= X-MC-Unique: RvBDhcJTOM26uZFVRVuLfw-1 From: Paolo Bonzini To: qemu-devel@nongnu.org Subject: [PULL 051/115] target/i386: implement special cases for fxtract Date: Thu, 11 Jun 2020 15:43:45 -0400 Message-Id: <20200611194449.31468-52-pbonzini@redhat.com> In-Reply-To: <20200611194449.31468-1-pbonzini@redhat.com> References: <20200611194449.31468-1-pbonzini@redhat.com> MIME-Version: 1.0 X-Scanned-By: MIMEDefang 2.79 on 10.5.11.13 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: quoted-printable Received-SPF: pass (zohomail.com: domain of gnu.org designates 209.51.188.17 as permitted sender) client-ip=209.51.188.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Received-SPF: pass client-ip=205.139.110.120; envelope-from=pbonzini@redhat.com; helo=us-smtp-1.mimecast.com X-detected-operating-system: by eggs.gnu.org: First seen = 2020/06/11 14:52:10 X-ACL-Warn: Detected OS = Linux 2.2.x-3.x [generic] [fuzzy] X-Spam_score_int: -30 X-Spam_score: -3.1 X-Spam_bar: --- X-Spam_report: (-3.1 / 5.0 requ) BAYES_00=-1.9, DKIMWL_WL_HIGH=-1, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, RCVD_IN_DNSWL_NONE=-0.0001, RCVD_IN_MSPIKE_H4=-0.01, RCVD_IN_MSPIKE_WL=-0.01, SPF_HELO_NONE=0.001, SPF_PASS=-0.001 autolearn=_AUTOLEARN X-Spam_action: no action X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?UTF-8?q?Alex=20Benn=C3=A9e?= , Joseph Myers Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail-DKIM: fail (Header signature does not verify) From: Joseph Myers The implementation of the fxtract instruction treats all nonzero operands as normal numbers, so yielding incorrect results for invalid formats, infinities, NaNs and subnormal and pseudo-denormal operands. Implement appropriate handling of all those cases. Signed-off-by: Joseph Myers Acked-by: Alex Benn=C3=A9e Message-Id: Signed-off-by: Paolo Bonzini --- target/i386/fpu_helper.c | 25 +++++- tests/tcg/i386/test-i386-fxtract.c | 120 +++++++++++++++++++++++++++++ 2 files changed, 144 insertions(+), 1 deletion(-) create mode 100644 tests/tcg/i386/test-i386-fxtract.c diff --git a/target/i386/fpu_helper.c b/target/i386/fpu_helper.c index b34fa784eb..568bd3b359 100644 --- a/target/i386/fpu_helper.c +++ b/target/i386/fpu_helper.c @@ -767,10 +767,33 @@ void helper_fxtract(CPUX86State *env) &env->fp_status); fpush(env); ST0 =3D temp.d; + } else if (floatx80_invalid_encoding(ST0)) { + float_raise(float_flag_invalid, &env->fp_status); + ST0 =3D floatx80_default_nan(&env->fp_status); + fpush(env); + ST0 =3D ST1; + } else if (floatx80_is_any_nan(ST0)) { + if (floatx80_is_signaling_nan(ST0, &env->fp_status)) { + float_raise(float_flag_invalid, &env->fp_status); + ST0 =3D floatx80_silence_nan(ST0, &env->fp_status); + } + fpush(env); + ST0 =3D ST1; + } else if (floatx80_is_infinity(ST0)) { + fpush(env); + ST0 =3D ST1; + ST1 =3D floatx80_infinity; } else { int expdif; =20 - expdif =3D EXPD(temp) - EXPBIAS; + if (EXPD(temp) =3D=3D 0) { + int shift =3D clz64(temp.l.lower); + temp.l.lower <<=3D shift; + expdif =3D 1 - EXPBIAS - shift; + float_raise(float_flag_input_denormal, &env->fp_status); + } else { + expdif =3D EXPD(temp) - EXPBIAS; + } /* DP exponent bias */ ST0 =3D int32_to_floatx80(expdif, &env->fp_status); fpush(env); diff --git a/tests/tcg/i386/test-i386-fxtract.c b/tests/tcg/i386/test-i386-= fxtract.c new file mode 100644 index 0000000000..64fd93d333 --- /dev/null +++ b/tests/tcg/i386/test-i386-fxtract.c @@ -0,0 +1,120 @@ +/* Test fxtract instruction. */ + +#include +#include + +union u { + struct { uint64_t sig; uint16_t sign_exp; } s; + long double ld; +}; + +volatile union u ld_pseudo_m16382 =3D { .s =3D { UINT64_C(1) << 63, 0 } }; +volatile union u ld_invalid_1 =3D { .s =3D { 1, 1234 } }; +volatile union u ld_invalid_2 =3D { .s =3D { 0, 1234 } }; +volatile union u ld_invalid_3 =3D { .s =3D { 0, 0x7fff } }; +volatile union u ld_invalid_4 =3D { .s =3D { (UINT64_C(1) << 63) - 1, 0x7f= ff } }; + +volatile long double ld_sig, ld_exp; + +int isnan_ld(long double x) +{ + union u tmp =3D { .ld =3D x }; + return ((tmp.s.sign_exp & 0x7fff) =3D=3D 0x7fff && + (tmp.s.sig >> 63) !=3D 0 && + (tmp.s.sig << 1) !=3D 0); +} + +int issignaling_ld(long double x) +{ + union u tmp =3D { .ld =3D x }; + return isnan_ld(x) && (tmp.s.sig & UINT64_C(0x4000000000000000)) =3D= =3D 0; +} + +int main(void) +{ + int ret =3D 0; + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : "0" (= 2.5L)); + if (ld_sig !=3D 1.25L || ld_exp !=3D 1.0L) { + printf("FAIL: fxtract 2.5\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : "0" (= 0.0L)); + if (ld_sig !=3D 0.0L || __builtin_copysignl(1.0L, ld_sig) !=3D 1.0L || + ld_exp !=3D -__builtin_infl()) { + printf("FAIL: fxtract 0.0\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : "0" (= -0.0L)); + if (ld_sig !=3D -0.0L || __builtin_copysignl(1.0L, ld_sig) !=3D -1.0L = || + ld_exp !=3D -__builtin_infl()) { + printf("FAIL: fxtract -0.0\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (__builtin_infl())); + if (ld_sig !=3D __builtin_infl() || ld_exp !=3D __builtin_infl()) { + printf("FAIL: fxtract inf\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (-__builtin_infl())); + if (ld_sig !=3D -__builtin_infl() || ld_exp !=3D __builtin_infl()) { + printf("FAIL: fxtract -inf\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (__builtin_nanl(""))); + if (!isnan_ld(ld_sig) || issignaling_ld(ld_sig) || + !isnan_ld(ld_exp) || issignaling_ld(ld_exp)) { + printf("FAIL: fxtract qnan\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (__builtin_nansl(""))); + if (!isnan_ld(ld_sig) || issignaling_ld(ld_sig) || + !isnan_ld(ld_exp) || issignaling_ld(ld_exp)) { + printf("FAIL: fxtract snan\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (0x1p-16445L)); + if (ld_sig !=3D 1.0L || ld_exp !=3D -16445.0L) { + printf("FAIL: fxtract subnormal\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (ld_pseudo_m16382.ld)); + if (ld_sig !=3D 1.0L || ld_exp !=3D -16382.0L) { + printf("FAIL: fxtract pseudo\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (ld_invalid_1.ld)); + if (!isnan_ld(ld_sig) || issignaling_ld(ld_sig) || + !isnan_ld(ld_exp) || issignaling_ld(ld_exp)) { + printf("FAIL: fxtract invalid 1\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (ld_invalid_2.ld)); + if (!isnan_ld(ld_sig) || issignaling_ld(ld_sig) || + !isnan_ld(ld_exp) || issignaling_ld(ld_exp)) { + printf("FAIL: fxtract invalid 2\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (ld_invalid_3.ld)); + if (!isnan_ld(ld_sig) || issignaling_ld(ld_sig) || + !isnan_ld(ld_exp) || issignaling_ld(ld_exp)) { + printf("FAIL: fxtract invalid 3\n"); + ret =3D 1; + } + __asm__ volatile ("fxtract" : "=3Dt" (ld_sig), "=3Du" (ld_exp) : + "0" (ld_invalid_4.ld)); + if (!isnan_ld(ld_sig) || issignaling_ld(ld_sig) || + !isnan_ld(ld_exp) || issignaling_ld(ld_exp)) { + printf("FAIL: fxtract invalid 4\n"); + ret =3D 1; + } + return ret; +} --=20 2.26.2