1 /* 2 * QEMU TCG support -- s390x vector floating point instruction support 3 * 4 * Copyright (C) 2019 Red Hat Inc 5 * 6 * Authors: 7 * David Hildenbrand <david@redhat.com> 8 * 9 * This work is licensed under the terms of the GNU GPL, version 2 or later. 10 * See the COPYING file in the top-level directory. 11 */ 12 #include "qemu/osdep.h" 13 #include "qemu-common.h" 14 #include "cpu.h" 15 #include "internal.h" 16 #include "vec.h" 17 #include "tcg_s390x.h" 18 #include "tcg/tcg-gvec-desc.h" 19 #include "exec/exec-all.h" 20 #include "exec/helper-proto.h" 21 #include "fpu/softfloat.h" 22 23 #define VIC_INVALID 0x1 24 #define VIC_DIVBYZERO 0x2 25 #define VIC_OVERFLOW 0x3 26 #define VIC_UNDERFLOW 0x4 27 #define VIC_INEXACT 0x5 28 29 /* returns the VEX. If the VEX is 0, there is no trap */ 30 static uint8_t check_ieee_exc(CPUS390XState *env, uint8_t enr, bool XxC, 31 uint8_t *vec_exc) 32 { 33 uint8_t vece_exc = 0, trap_exc; 34 unsigned qemu_exc; 35 36 /* Retrieve and clear the softfloat exceptions */ 37 qemu_exc = env->fpu_status.float_exception_flags; 38 if (qemu_exc == 0) { 39 return 0; 40 } 41 env->fpu_status.float_exception_flags = 0; 42 43 vece_exc = s390_softfloat_exc_to_ieee(qemu_exc); 44 45 /* Add them to the vector-wide s390x exception bits */ 46 *vec_exc |= vece_exc; 47 48 /* Check for traps and construct the VXC */ 49 trap_exc = vece_exc & env->fpc >> 24; 50 if (trap_exc) { 51 if (trap_exc & S390_IEEE_MASK_INVALID) { 52 return enr << 4 | VIC_INVALID; 53 } else if (trap_exc & S390_IEEE_MASK_DIVBYZERO) { 54 return enr << 4 | VIC_DIVBYZERO; 55 } else if (trap_exc & S390_IEEE_MASK_OVERFLOW) { 56 return enr << 4 | VIC_OVERFLOW; 57 } else if (trap_exc & S390_IEEE_MASK_UNDERFLOW) { 58 return enr << 4 | VIC_UNDERFLOW; 59 } else if (!XxC) { 60 g_assert(trap_exc & S390_IEEE_MASK_INEXACT); 61 /* inexact has lowest priority on traps */ 62 return enr << 4 | VIC_INEXACT; 63 } 64 } 65 return 0; 66 } 67 68 static void handle_ieee_exc(CPUS390XState *env, uint8_t vxc, uint8_t vec_exc, 69 uintptr_t retaddr) 70 { 71 if (vxc) { 72 /* on traps, the fpc flags are not updated, instruction is suppressed */ 73 tcg_s390_vector_exception(env, vxc, retaddr); 74 } 75 if (vec_exc) { 76 /* indicate exceptions for all elements combined */ 77 env->fpc |= vec_exc << 16; 78 } 79 } 80 81 typedef uint64_t (*vop64_3_fn)(uint64_t a, uint64_t b, float_status *s); 82 static void vop64_3(S390Vector *v1, const S390Vector *v2, const S390Vector *v3, 83 CPUS390XState *env, bool s, vop64_3_fn fn, 84 uintptr_t retaddr) 85 { 86 uint8_t vxc, vec_exc = 0; 87 S390Vector tmp = {}; 88 int i; 89 90 for (i = 0; i < 2; i++) { 91 const uint64_t a = s390_vec_read_element64(v2, i); 92 const uint64_t b = s390_vec_read_element64(v3, i); 93 94 s390_vec_write_element64(&tmp, i, fn(a, b, &env->fpu_status)); 95 vxc = check_ieee_exc(env, i, false, &vec_exc); 96 if (s || vxc) { 97 break; 98 } 99 } 100 handle_ieee_exc(env, vxc, vec_exc, retaddr); 101 *v1 = tmp; 102 } 103 104 static uint64_t vfa64(uint64_t a, uint64_t b, float_status *s) 105 { 106 return float64_add(a, b, s); 107 } 108 109 void HELPER(gvec_vfa64)(void *v1, const void *v2, const void *v3, 110 CPUS390XState *env, uint32_t desc) 111 { 112 vop64_3(v1, v2, v3, env, false, vfa64, GETPC()); 113 } 114 115 void HELPER(gvec_vfa64s)(void *v1, const void *v2, const void *v3, 116 CPUS390XState *env, uint32_t desc) 117 { 118 vop64_3(v1, v2, v3, env, true, vfa64, GETPC()); 119 } 120