Add a test to prevent regressions. Data is generated using a
libFuzzer-based fuzzer and hopefully covers all the important corner
cases.
Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com>
---
tests/tcg/s390x/Makefile.target | 3 +
tests/tcg/s390x/divide-to-integer.c | 215 ++++++++++++++++++++++++++++
2 files changed, 218 insertions(+)
create mode 100644 tests/tcg/s390x/divide-to-integer.c
diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target
index da5fe71a407..d5ec01d04fd 100644
--- a/tests/tcg/s390x/Makefile.target
+++ b/tests/tcg/s390x/Makefile.target
@@ -49,14 +49,17 @@ TESTS+=cvd
TESTS+=cvb
TESTS+=ts
TESTS+=ex-smc
+TESTS+=divide-to-integer
cdsg: CFLAGS+=-pthread
cdsg: LDFLAGS+=-pthread
rxsbg: CFLAGS+=-O2
+divide-to-integer: CFLAGS+=-O2
cgebra: LDFLAGS+=-lm
clgebr: LDFLAGS+=-lm
+divide-to-integer: LDFLAGS+=-lm
include $(S390X_SRC)/pgm-specification.mak
$(PGM_SPECIFICATION_TESTS): pgm-specification-user.o
diff --git a/tests/tcg/s390x/divide-to-integer.c b/tests/tcg/s390x/divide-to-integer.c
new file mode 100644
index 00000000000..49a18d07b31
--- /dev/null
+++ b/tests/tcg/s390x/divide-to-integer.c
@@ -0,0 +1,215 @@
+/*
+ * Test DIEBR and DIDBR instructions.
+ *
+ * Most inputs were discovered by fuzzing and exercise various corner cases in
+ * the helpers.
+ *
+ * SPDX-License-Identifier: GPL-2.0-or-later
+ */
+#include <signal.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <asm/ucontext.h>
+
+static void sigfpe_handler(int sig, siginfo_t *info, void *puc)
+{
+ struct ucontext *uc = puc;
+ unsigned short *xr_insn;
+ int r;
+
+ xr_insn = (unsigned short *)(uc->uc_mcontext.regs.psw.addr - 6);
+ r = *xr_insn & 0xf;
+ uc->uc_mcontext.regs.gprs[r] = sig;
+}
+
+#define DIVIDE_TO_INTEGER(name, floatN) \
+static inline __attribute__((__always_inline__)) int \
+name(floatN *r1, floatN r2, floatN *r3, int m4, int *sig) \
+{ \
+ int cc; \
+ \
+ asm(/* Make the initial CC predictable for suppression tests */ \
+ "xr %[sig],%[sig]\n" \
+ #name " %[r1],%[r3],%[r2],%[m4]\n" \
+ "ipm %[cc]\n" \
+ "srl %[cc],28" \
+ /* \
+ * Use earlyclobbers to prevent the compiler from reusing floating \
+ * point registers. This instruction doesn't like it. \
+ */ \
+ : [r1] "+&f" (*r1), [r3] "+&f" (*r3), [sig] "=r" (*sig), [cc] "=d" (cc)\
+ : [r2] "f" (r2), [m4] "i" (m4) \
+ : "cc"); \
+ \
+ return cc; \
+}
+
+DIVIDE_TO_INTEGER(diebr, float)
+DIVIDE_TO_INTEGER(didbr, double)
+
+#define TEST_DIVIDE_TO_INTEGER(name, intN, int_fmt, floatN, float_fmt) \
+static inline __attribute__((__always_inline__)) int \
+test_ ## name(unsigned intN r1i, unsigned intN r2i, int m4, int fpc, \
+ unsigned intN r1o, unsigned intN r3o, int cco, unsigned int fpco,\
+ int sigo) \
+{ \
+ union { \
+ floatN f; \
+ unsigned intN i; \
+ } r1, r2, r3; \
+ int cc, err = 0, sig; \
+ \
+ r1.i = r1i; \
+ r2.i = r2i; \
+ r3.i = 0x12345678; \
+ printf("[ RUN ] %" float_fmt "(0x%" int_fmt \
+ ") / %" float_fmt "(0x%" int_fmt ")\n", r1.f, r1.i, r2.f, r2.i); \
+ asm volatile("sfpc %[fpc]" : : [fpc] "r" (fpc)); \
+ cc = name(&r1.f, r2.f, &r3.f, m4, &sig); \
+ asm volatile("stfpc %[fpc]" : [fpc] "=Q" (fpc)); \
+ if (r1.i != r1o) { \
+ printf("[ FAILED ] remainder 0x%" int_fmt \
+ " != expected 0x%" int_fmt "\n", r1.i, r1o); \
+ err += 1; \
+ } \
+ if (r3.i != r3o) { \
+ printf("[ FAILED ] quotient 0x%" int_fmt \
+ " != expected 0x%" int_fmt "\n", r3.i, r3o); \
+ err += 1; \
+ } \
+ if (cc != cco) { \
+ printf("[ FAILED ] cc %d != expected %d\n", cc, cco); \
+ err += 1; \
+ } \
+ if (fpc != fpco) { \
+ printf("[ FAILED ] fpc 0x%x != expected 0x%x\n", fpc, fpco); \
+ err += 1; \
+ } \
+ if (sig != sigo) { \
+ printf("[ FAILED ] signal 0x%x != expected 0x%x\n", sig, sigo); \
+ err += 1; \
+ } \
+ \
+ return err; \
+}
+
+TEST_DIVIDE_TO_INTEGER(diebr, int, "x", float, "f")
+TEST_DIVIDE_TO_INTEGER(didbr, long, "lx", double, "lf")
+
+int main(void)
+{
+ struct sigaction act = {
+ .sa_sigaction = sigfpe_handler,
+ .sa_flags = SA_SIGINFO,
+ };
+ int err = 0;
+
+ /* Set up SIG handler */
+ if (sigaction(SIGFPE, &act, NULL)) {
+ printf("[ FAILED ] sigaction(SIGFPE) failed\n");
+ return EXIT_FAILURE;
+ }
+
+ /* 451 / 460 */
+ err += test_diebr(0x43e1f1f1, 0x43e61616, 7, 0,
+ 0x43e1f1f1, 0, 0, 0, 0);
+
+ /* 480 / 0 */
+ err += test_diebr(0x43f00000, 0, 0, 0,
+ 0x7fc00000, 0x7fc00000, 1, 0x800000, 0);
+
+ /* QNaN / QNaN */
+ err += test_diebr(0xffffffff, 0xffffffff, 0, 0,
+ 0xffffffff, 0xffffffff, 1, 0, 0);
+
+ /* -2.08E-8 / -2.08E-8 */
+ err += test_diebr(0xb2b2b2b2, 0xb2b2b2b2, 0, 0,
+ 0x80000000, 0x3f800000, 0, 0, 0);
+
+ /* 4.62E-2 / -7.94E-11 */
+ err += test_diebr(0x3d3d3d3d, 0xaeaeaeae, 0, 0,
+ 0x2f38b8c0, 0xce0aaaab, 2, 0, 0);
+
+ /* 1.07E-31 / 2.19 */
+ err += test_diebr(0x0c0c0c0c, 0x400c0c0c, 6, 0,
+ 0xc00c0c0c, 0x3f800000, 0, 0x80000, 0);
+
+ /* 2.98E+29 / -5.7E-29 */
+ err += test_diebr(0x7070ffff, 0x90909090, 0, 0,
+ 0x6431c0c0, 0xbf5562aa, 3, 0, 0);
+
+ /* -2.19E-5 / 2.58E-26 */
+ err += test_diebr(0xb7b7b7b7, 0x15000000, 7, 0,
+ 0x80000000, 0xe237b7b7, 0, 0, 0);
+
+ /* 0 / 0 */
+ err += test_diebr(0, 0, 1, 0,
+ 0x7fc00000, 0x7fc00000, 1, 0x800000, 0);
+
+ /* 4.3E-33 / -2.08E-8 with SIGFPE */
+ err += test_diebr(0x09b2b2b2, 0xb2b2b2b2, 0, 0xfc000007,
+ 0xb2b2b2b1, 0xbf800000, 0, 0xfc000807, SIGFPE);
+
+ /* 1.19E-39 / -1.28E-9 */
+ err += test_diebr(0x000d0100, 0xb0b0b0b0, 6, 0xfc000000,
+ 0x5ed01000, 0x80000000, 0, 0xfc001000, SIGFPE);
+
+ /* 5.35E+7 / -5.21E+20 */
+ err += test_diebr(0x4c4c4c4c, 0xe1e1e1e1, 0, 0xfc000007,
+ 0xe1e1e1e1, 0xbf800000, 0, 0xfc000c07, SIGFPE);
+
+ /* 0 / 0 with SIGFPE */
+ err += test_diebr(0, 0, 0, 0xfc000007,
+ 0, 0x12345678, 0, 0xfc008007, SIGFPE);
+
+ /* 5.76E-16 / 5.39E+34 */
+ err += test_diebr(0x26262626, 0x79262626, 6, 0,
+ 0xf9262626, 0x3f800000, 0, 0x80000, 0);
+
+ /* -4.97E+17 / 2.03E-38 */
+ err += test_diebr(0xdcdcdcdc, 0x00dcdcdc, 7, 0xfc000000,
+ 0x80000000, 0xbb800000, 1, 0xfc000000, 0);
+
+ /* -1.23E+17 / SNaN */
+ err += test_diebr(0xdbdb240b, 0xffac73ff, 4, 0,
+ 0xffec73ff, 0xffec73ff, 1, 0x800000, 0);
+
+ /* 2.34E-38 / 3.27E-33 with SIGFPE */
+ err += test_diebr(0x00ff0987, 0x0987c6f6, 6, 0x08000000,
+ 0x8987c6b6, 0x3f800000, 0, 0x8000800, SIGFPE);
+
+ /* -5.93E+11 / -2.7E+4 */
+ err += test_diebr(0xd30a0040, 0xc6d30a00, 0, 0xc4000000,
+ 0xc74a4400, 0x4ba766c6, 2, 0xc4000000, 0);
+
+ /* 9.86E-32 / -inf */
+ err += test_diebr(0x0c000029, 0xff800000, 0, 0,
+ 0xc000029, 0x80000000, 0, 0, 0);
+
+ /* QNaN / SNaN */
+ err += test_diebr(0xffff94ff, 0xff94ff24, 4, 7,
+ 0xffd4ff24, 0xffd4ff24, 1, 0x800007, 0);
+
+ /* 2.8E-43 / -inf */
+ err += test_diebr(0x000000c8, 0xff800000, 0, 0x7c000007,
+ 0x000000c8, 0x80000000, 0, 0x7c000007, 0);
+
+ /* -1.7E+38 / -inf */
+ err += test_diebr(0xff00003d, 0xff800000, 0, 0,
+ 0xff00003d, 0, 0, 0, 0);
+
+ /* 1.94E-304 / 1.94E-304 */
+ err += test_didbr(0x00e100e100e100e1, 0x00e100e100e100e1, 0, 1,
+ 0, 0x3ff0000000000000, 0, 1, 0);
+
+ /* 4.82E-299 / 5.29E-308 */
+ err += test_didbr(0x0200230200230200, 0x0023020023020023, 0, 0,
+ 0x8001a017d247b3f4, 0x41cb2aa05f000000, 0, 0, 0);
+
+ /* -1.38E-75 / -3.77E+208 */
+ err += test_didbr(0xb063eb3d63b063eb, 0xeb3d63b063eb3d63, 3, 0xe8000000,
+ 0x6b3d63b063eb3d63, 0x3ff0000000000000, 0, 0xe8000c00,
+ SIGFPE);
+
+ return err ? EXIT_FAILURE : EXIT_SUCCESS;
+}
--
2.52.0Ilya Leoshkevich <iii@linux.ibm.com> writes: > Add a test to prevent regressions. Data is generated using a > libFuzzer-based fuzzer and hopefully covers all the important corner > cases. > > Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> > --- > tests/tcg/s390x/Makefile.target | 3 + > tests/tcg/s390x/divide-to-integer.c | 215 ++++++++++++++++++++++++++++ > 2 files changed, 218 insertions(+) > create mode 100644 tests/tcg/s390x/divide-to-integer.c > > diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target > index da5fe71a407..d5ec01d04fd 100644 > --- a/tests/tcg/s390x/Makefile.target > +++ b/tests/tcg/s390x/Makefile.target > @@ -49,14 +49,17 @@ TESTS+=cvd > TESTS+=cvb > TESTS+=ts > TESTS+=ex-smc > +TESTS+=divide-to-integer > > cdsg: CFLAGS+=-pthread > cdsg: LDFLAGS+=-pthread > > rxsbg: CFLAGS+=-O2 > +divide-to-integer: CFLAGS+=-O2 As we generally compile -O0 to make life easier for people debugging behaviour via gdbstub could we have an explanation of why -O2 is needed here? Is it the same reason as rxsbg? <snip> -- Alex Bennée Virtualisation Tech Lead @ Linaro
On 1/22/26 17:43, Alex Bennée wrote: > Ilya Leoshkevich <iii@linux.ibm.com> writes: > >> Add a test to prevent regressions. Data is generated using a >> libFuzzer-based fuzzer and hopefully covers all the important corner >> cases. >> >> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> >> --- >> tests/tcg/s390x/Makefile.target | 3 + >> tests/tcg/s390x/divide-to-integer.c | 215 ++++++++++++++++++++++++++++ >> 2 files changed, 218 insertions(+) >> create mode 100644 tests/tcg/s390x/divide-to-integer.c >> >> diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target >> index da5fe71a407..d5ec01d04fd 100644 >> --- a/tests/tcg/s390x/Makefile.target >> +++ b/tests/tcg/s390x/Makefile.target >> @@ -49,14 +49,17 @@ TESTS+=cvd >> TESTS+=cvb >> TESTS+=ts >> TESTS+=ex-smc >> +TESTS+=divide-to-integer >> >> cdsg: CFLAGS+=-pthread >> cdsg: LDFLAGS+=-pthread >> >> rxsbg: CFLAGS+=-O2 >> +divide-to-integer: CFLAGS+=-O2 > As we generally compile -O0 to make life easier for people debugging > behaviour via gdbstub could we have an explanation of why -O2 is needed > here? Is it the same reason as rxsbg? > > <snip> Yes, this is because inlining is mandatory for the mask argument, and -O0 does not honor always_inline.
Ilya Leoshkevich <iii@linux.ibm.com> writes: > On 1/22/26 17:43, Alex Bennée wrote: >> Ilya Leoshkevich <iii@linux.ibm.com> writes: >> >>> Add a test to prevent regressions. Data is generated using a >>> libFuzzer-based fuzzer and hopefully covers all the important corner >>> cases. >>> >>> Signed-off-by: Ilya Leoshkevich <iii@linux.ibm.com> >>> --- >>> tests/tcg/s390x/Makefile.target | 3 + >>> tests/tcg/s390x/divide-to-integer.c | 215 ++++++++++++++++++++++++++++ >>> 2 files changed, 218 insertions(+) >>> create mode 100644 tests/tcg/s390x/divide-to-integer.c >>> >>> diff --git a/tests/tcg/s390x/Makefile.target b/tests/tcg/s390x/Makefile.target >>> index da5fe71a407..d5ec01d04fd 100644 >>> --- a/tests/tcg/s390x/Makefile.target >>> +++ b/tests/tcg/s390x/Makefile.target >>> @@ -49,14 +49,17 @@ TESTS+=cvd >>> TESTS+=cvb >>> TESTS+=ts >>> TESTS+=ex-smc >>> +TESTS+=divide-to-integer >>> cdsg: CFLAGS+=-pthread >>> cdsg: LDFLAGS+=-pthread >>> rxsbg: CFLAGS+=-O2 >>> +divide-to-integer: CFLAGS+=-O2 >> As we generally compile -O0 to make life easier for people debugging >> behaviour via gdbstub could we have an explanation of why -O2 is needed >> here? Is it the same reason as rxsbg? >> >> <snip> > > Yes, this is because inlining is mandatory for the mask argument, and > -O0 does not honor always_inline. Could we add a comment to that effect in the Makefile. Otherwise looks fine to me: Acked-by: Alex Bennée <alex.bennee@linaro.org> -- Alex Bennée Virtualisation Tech Lead @ Linaro
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