From 374ff4d0a3c2cce2bc6e4ba8a77eaba55c165252 Mon Sep 17 00:00:00 2001 From: Joseph Myers Date: Wed, 13 May 2020 23:51:42 +0000 Subject: [PATCH] target/i386: fix fbstp handling of out-of-range values The fbstp implementation fails to check for out-of-range and invalid values, instead just taking the result of conversion to int64_t and storing its sign and low 18 decimal digits. Fix this by checking for an out-of-range result (invalid conversions always result in INT64_MAX or INT64_MIN from the softfloat code, which are large enough to be considered as out-of-range by this code) and storing the packed BCD indefinite encoding in that case. Signed-off-by: Joseph Myers Message-Id: Signed-off-by: Paolo Bonzini --- target/i386/fpu_helper.c | 10 +++ tests/tcg/i386/test-i386-fbstp.c | 115 +++++++++++++++++++++++++++++++ 2 files changed, 125 insertions(+) diff --git a/target/i386/fpu_helper.c b/target/i386/fpu_helper.c index f0a57099ca..41f6f391ca 100644 --- a/target/i386/fpu_helper.c +++ b/target/i386/fpu_helper.c @@ -732,6 +732,16 @@ void helper_fbst_ST0(CPUX86State *env, target_ulong ptr) val = floatx80_to_int64(ST0, &env->fp_status); mem_ref = ptr; + if (val >= 1000000000000000000LL || val <= -1000000000000000000LL) { + float_raise(float_flag_invalid, &env->fp_status); + while (mem_ref < ptr + 7) { + cpu_stb_data_ra(env, mem_ref++, 0, GETPC()); + } + cpu_stb_data_ra(env, mem_ref++, 0xc0, GETPC()); + cpu_stb_data_ra(env, mem_ref++, 0xff, GETPC()); + cpu_stb_data_ra(env, mem_ref++, 0xff, GETPC()); + return; + } mem_end = mem_ref + 9; if (SIGND(temp)) { cpu_stb_data_ra(env, mem_end, 0x80, GETPC()); diff --git a/tests/tcg/i386/test-i386-fbstp.c b/tests/tcg/i386/test-i386-fbstp.c index d368949188..73bf56b9dc 100644 --- a/tests/tcg/i386/test-i386-fbstp.c +++ b/tests/tcg/i386/test-i386-fbstp.c @@ -1,8 +1,19 @@ /* Test fbstp instruction. */ +#include #include #include +union u { + struct { uint64_t sig; uint16_t sign_exp; } s; + long double ld; +}; + +volatile union u ld_invalid_1 = { .s = { 1, 1234 } }; +volatile union u ld_invalid_2 = { .s = { 0, 1234 } }; +volatile union u ld_invalid_3 = { .s = { 0, 0x7fff } }; +volatile union u ld_invalid_4 = { .s = { (UINT64_C(1) << 63) - 1, 0x7fff } }; + int main(void) { int ret = 0; @@ -21,5 +32,109 @@ int main(void) printf("FAIL: fbstp -0.1\n"); ret = 1; } + memset(out, 0x1f, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-987654321987654321.0L) : + "st"); + out[9] &= 0x80; + if (memcmp(out, "\x21\x43\x65\x87\x19\x32\x54\x76\x98\x80", + sizeof out) != 0) { + printf("FAIL: fbstp -987654321987654321\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (999999999999999999.5L) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp 999999999999999999.5\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (1000000000000000000.0L) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp 1000000000000000000\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (1e30L) : "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp 1e30\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-999999999999999999.5L) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp -999999999999999999.5\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-1000000000000000000.0L) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp -1000000000000000000\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-1e30L) : "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp -1e30\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (__builtin_infl()) : "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp inf\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-__builtin_infl()) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp -inf\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (__builtin_nanl("")) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp nan\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (-__builtin_nanl("")) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp -nan\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (ld_invalid_1.ld) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp invalid 1\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (ld_invalid_2.ld) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp invalid 2\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (ld_invalid_3.ld) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp invalid 3\n"); + ret = 1; + } + memset(out, 0x12, sizeof out); + __asm__ volatile ("fbstp %0" : "=m" (out) : "t" (ld_invalid_4.ld) : + "st"); + if (memcmp(out, "\0\0\0\0\0\0\0\xc0\xff\xff", sizeof out) != 0) { + printf("FAIL: fbstp invalid 4\n"); + ret = 1; + } return ret; }