Add a test to prevent regressions. Data is generated using a libFuzzer-based fuzzer and hopefully covers all the important corner cases.
Acked-by: Alex Bennée <[email protected]> Signed-off-by: Ilya Leoshkevich <[email protected]> --- tests/tcg/s390x/Makefile.target | 5 + tests/tcg/s390x/divide-to-integer.c | 265 ++++++++++++++++++++++++++++ 2 files changed, 270 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..0ca030ded01 100644 --- a/tests/tcg/s390x/Makefile.target +++ b/tests/tcg/s390x/Makefile.target @@ -49,14 +49,19 @@ TESTS+=cvd TESTS+=cvb TESTS+=ts TESTS+=ex-smc +TESTS+=divide-to-integer cdsg: CFLAGS+=-pthread cdsg: LDFLAGS+=-pthread +# The following tests contain inline assembly that requires inlining, +# and thus cannot be built with -O0. 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..62b4787ec0e --- /dev/null +++ b/tests/tcg/s390x/divide-to-integer.c @@ -0,0 +1,265 @@ +/* + * 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); + + /* + * Test partial remainder without quotient scaling (cc2). + * + * a = 12401981 / 268435456 + * b = -5723991 / 72057594037927936 + * q = a / b = -3329131425038336 / 5723991 =~ -581610178.1 + * n = round(q, float32, nearest_even) = -581610176 + * r_precise = a - b * n = 189155 / 1125899906842624 + * r = round(r_precise, float32, nearest_even) = r_precise + */ + 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); + + /* + * Test partial remainder with quotient scaling (cc3). + * + * a = 298343530578310714772108083200 + * b = -592137/10384593717069655257060992658440192 + * q = a / b + * = -1032725451057301340137043014721780674141077289604872315653324800 / + * 197379 + * =~ -5232195173029052432817285601415452880707052369324357280426.6 + * n = round(q, float32, nearest_even) + * = -5232194943010009439437691768433469154159343131709361094656 + * n / 2^192 = -6992213 / 8388608 + * r_precise = a - b * n = 13115851209189604982784 + * r = round(r_precise, float32, nearest_even) = r_precise + */ + err += test_diebr(0x7070ffff, 0x90909090, 0, 0, + 0x6431c0c0, 0xbf5562aa, 3, 0, 0); + + /* + * Test large, but representable quotient. + * + * a = -12040119 / 549755813888 + * b = 1 / 38685626227668133590597632 + * q = a / b = -847248053779631702016 + * n = round(q, float32, to_odd) = q + * r_precise = a - b * n = -0 + * r = round(r_precise, float32, nearest_even) = -0 + */ + 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); + + /* + * Test tiny remainder scaling when FPC Underflow Mask is set. + * + * 1.19E-39 / -1.28E-9 = { r = 1.19E-39 * 2^192, n = -0 } + */ + err += test_diebr(0x000d0100, 0xb0b0b0b0, 6, 0xfc000000, + 0x5ed01000, 0x80000000, 0, 0xfc001000, SIGFPE); + + /* + * Test "inexact and incremented" DXC. + * + * a = 53555504 + * b = -520849213389117849600 + * q = a / b = -3347219 / 32553075836819865600 + * n = round(q, float32, to_odd) = -1 + * r_precise = a - b * n = -520849213389064294096 + * r = round(r_precise, float32, to_odd) = -520849213389117849600 + * abs(r) - abs(r_precise) = 53555504 + */ + 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); + + /* 4.78E-299 / 6.88E-315 */ + err += test_didbr(0x0200000000000000, 0x0000000053020000, 0, 0, + 0x8000000020820000, 0x4338ac20dd47c6c1, 0, 0, 0); + + return err ? EXIT_FAILURE : EXIT_SUCCESS; +} -- 2.52.0
