x86/fpu/math-emu, selftests: Add tests for FCMOV and FCOMI insns

Signed-off-by: Denys Vlasenko <dvlasenk@redhat.com>
Cc: Andy Lutomirski <luto@amacapital.net>
Cc: Borislav Petkov <bp@alien8.de>
Cc: Brian Gerst <brgerst@gmail.com>
Cc: H. Peter Anvin <hpa@zytor.com>
Cc: Kees Cook <keescook@chromium.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Shuah Khan <shuahkh@osg.samsung.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/r/1442494933-13798-1-git-send-email-dvlasenk@redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

1 files changed, 331 insertions, 0 deletions

diff --git a/tools/testing/selftests/x86/test_FCOMI.c b/tools/testing/selftests/x86/test_FCOMI.c
new file mode 100644
index 000000000000..db4933e31af9
--- /dev/null
+++ b/tools/testing/selftests/x86/test_FCOMI.c
@@ -0,0 +1,331 @@
+#undef _GNU_SOURCE
+#define _GNU_SOURCE 1
+#undef __USE_GNU
+#define __USE_GNU 1
+#include <unistd.h>
+#include <stdlib.h>
+#include <string.h>
+#include <stdio.h>
+#include <signal.h>
+#include <sys/types.h>
+#include <sys/select.h>
+#include <sys/time.h>
+#include <sys/wait.h>
+#include <fenv.h>
+
+enum {
+	CF = 1 << 0,
+	PF = 1 << 2,
+	ZF = 1 << 6,
+	ARITH = CF | PF | ZF,
+};
+
+long res_fcomi_pi_1;
+long res_fcomi_1_pi;
+long res_fcomi_1_1;
+long res_fcomi_nan_1;
+/* sNaN is s|111 1111 1|1xx xxxx xxxx xxxx xxxx xxxx */
+/* qNaN is s|111 1111 1|0xx xxxx xxxx xxxx xxxx xxxx (some x must be nonzero) */
+int snan = 0x7fc11111;
+int qnan = 0x7f811111;
+unsigned short snan1[5];
+/* sNaN80 is s|111 1111 1111 1111 |10xx xx...xx (some x must be nonzero) */
+unsigned short snan80[5] = { 0x1111, 0x1111, 0x1111, 0x8111, 0x7fff };
+
+int test(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+
+	"	push	%0""\n"
+	"	popf""\n"
+	"	fld1""\n"
+	"	fldpi""\n"
+	"	fcomi	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	ffree	%%st(1)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_1_pi""\n"
+
+	"	push	%0""\n"
+	"	popf""\n"
+	"	fldpi""\n"
+	"	fld1""\n"
+	"	fcomi	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	ffree	%%st(1)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_pi_1""\n"
+
+	"	push	%0""\n"
+	"	popf""\n"
+	"	fld1""\n"
+	"	fld1""\n"
+	"	fcomi	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	ffree	%%st(1)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_1_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_1_pi & ARITH) != (0)) {
+		printf("[BAD]\tfcomi_1_pi with flags:%lx\n", flags);
+		return 1;
+	}
+	if ((res_fcomi_pi_1 & ARITH) != (CF)) {
+		printf("[BAD]\tfcomi_pi_1 with flags:%lx->%lx\n", flags, res_fcomi_pi_1 & ARITH);
+		return 1;
+	}
+	if ((res_fcomi_1_1 & ARITH) != (ZF)) {
+		printf("[BAD]\tfcomi_1_1 with flags:%lx\n", flags);
+		return 1;
+	}
+	if (fetestexcept(FE_INVALID) != 0) {
+		printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+int test_qnan(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+	"	push	%0""\n"
+	"	popf""\n"
+	"	flds	qnan""\n"
+	"	fld1""\n"
+	"	fnclex""\n"		// fld of a qnan raised FE_INVALID, clear it
+	"	fcomi	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	ffree	%%st(1)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_nan_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
+		printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
+		return 1;
+	}
+	if (fetestexcept(FE_INVALID) != FE_INVALID) {
+		printf("[BAD]\tFE_INVALID is not set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+int testu_qnan(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+	"	push	%0""\n"
+	"	popf""\n"
+	"	flds	qnan""\n"
+	"	fld1""\n"
+	"	fnclex""\n"		// fld of a qnan raised FE_INVALID, clear it
+	"	fucomi	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	ffree	%%st(1)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_nan_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
+		printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
+		return 1;
+	}
+	if (fetestexcept(FE_INVALID) != 0) {
+		printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+int testu_snan(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+	"	push	%0""\n"
+	"	popf""\n"
+//	"	flds	snan""\n"	// WRONG, this will convert 32-bit fp snan to a *qnan* in 80-bit fp register!
+//	"	fstpt	snan1""\n"	// if uncommented, it prints "snan1:7fff c111 1100 0000 0000" - c111, not 8111!
+//	"	fnclex""\n"		// flds of a snan raised FE_INVALID, clear it
+	"	fldt	snan80""\n"	// fldt never raise FE_INVALID
+	"	fld1""\n"
+	"	fucomi	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	ffree	%%st(1)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_nan_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
+		printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
+		return 1;
+	}
+//	printf("snan:%x snan1:%04x %04x %04x %04x %04x\n", snan, snan1[4], snan1[3], snan1[2], snan1[1], snan1[0]);
+	if (fetestexcept(FE_INVALID) != FE_INVALID) {
+		printf("[BAD]\tFE_INVALID is not set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+int testp(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+
+	"	push	%0""\n"
+	"	popf""\n"
+	"	fld1""\n"
+	"	fldpi""\n"
+	"	fcomip	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_1_pi""\n"
+
+	"	push	%0""\n"
+	"	popf""\n"
+	"	fldpi""\n"
+	"	fld1""\n"
+	"	fcomip	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_pi_1""\n"
+
+	"	push	%0""\n"
+	"	popf""\n"
+	"	fld1""\n"
+	"	fld1""\n"
+	"	fcomip	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_1_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_1_pi & ARITH) != (0)) {
+		printf("[BAD]\tfcomi_1_pi with flags:%lx\n", flags);
+		return 1;
+	}
+	if ((res_fcomi_pi_1 & ARITH) != (CF)) {
+		printf("[BAD]\tfcomi_pi_1 with flags:%lx->%lx\n", flags, res_fcomi_pi_1 & ARITH);
+		return 1;
+	}
+	if ((res_fcomi_1_1 & ARITH) != (ZF)) {
+		printf("[BAD]\tfcomi_1_1 with flags:%lx\n", flags);
+		return 1;
+	}
+	if (fetestexcept(FE_INVALID) != 0) {
+		printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+int testp_qnan(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+	"	push	%0""\n"
+	"	popf""\n"
+	"	flds	qnan""\n"
+	"	fld1""\n"
+	"	fnclex""\n"		// fld of a qnan raised FE_INVALID, clear it
+	"	fcomip	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_nan_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
+		printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
+		return 1;
+	}
+	if (fetestexcept(FE_INVALID) != FE_INVALID) {
+		printf("[BAD]\tFE_INVALID is not set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+int testup_qnan(long flags)
+{
+	feclearexcept(FE_DIVBYZERO|FE_INEXACT|FE_INVALID|FE_OVERFLOW|FE_UNDERFLOW);
+
+	asm ("\n"
+	"	push	%0""\n"
+	"	popf""\n"
+	"	flds	qnan""\n"
+	"	fld1""\n"
+	"	fnclex""\n"		// fld of a qnan raised FE_INVALID, clear it
+	"	fucomip	%%st(1), %%st" "\n"
+	"	ffree	%%st(0)" "\n"
+	"	pushf""\n"
+	"	pop	res_fcomi_nan_1""\n"
+	:
+	: "r" (flags)
+	);
+	if ((res_fcomi_nan_1 & ARITH) != (ZF|CF|PF)) {
+		printf("[BAD]\tfcomi_qnan_1 with flags:%lx\n", flags);
+		return 1;
+	}
+	if (fetestexcept(FE_INVALID) != 0) {
+		printf("[BAD]\tFE_INVALID is set in %s\n", __func__);
+		return 1;
+	}
+	return 0;
+}
+
+void sighandler(int sig)
+{
+	printf("[FAIL]\tGot signal %d, exiting\n", sig);
+	exit(1);
+}
+
+int main(int argc, char **argv, char **envp)
+{
+	int err = 0;
+
+	/* SIGILL triggers on 32-bit kernels w/o fcomi emulation
+	 * when run with "no387 nofxsr". Other signals are caught
+	 * just in case.
+	 */
+	signal(SIGILL, sighandler);
+	signal(SIGFPE, sighandler);
+	signal(SIGSEGV, sighandler);
+
+	printf("[RUN]\tTesting f[u]comi[p] instructions\n");
+	err |= test(0);
+	err |= test_qnan(0);
+	err |= testu_qnan(0);
+	err |= testu_snan(0);
+	err |= test(CF|ZF|PF);
+	err |= test_qnan(CF|ZF|PF);
+	err |= testu_qnan(CF|ZF|PF);
+	err |= testu_snan(CF|ZF|PF);
+	err |= testp(0);
+	err |= testp_qnan(0);
+	err |= testup_qnan(0);
+	err |= testp(CF|ZF|PF);
+	err |= testp_qnan(CF|ZF|PF);
+	err |= testup_qnan(CF|ZF|PF);
+	if (!err)
+		printf("[OK]\tf[u]comi[p]\n");
+	else
+		printf("[FAIL]\tf[u]comi[p] errors: %d\n", err);
+
+	return err;
+}