Merge tag 'hppa-fpe-fixup-pull-request' of https://github.com/hdeller/qemu-hppa into staging

HPPA floating point exception handling fixes

Fixes and improvements in the floating point exception
handling in the hppa system and user emulation.

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* tag 'hppa-fpe-fixup-pull-request' of https://github.com/hdeller/qemu-hppa:
  target/hppa: Fix FPE exceptions
  linux-user/hppa: Send proper si_code on SIGFPE exception
  target/hppa: Copy instruction code into fr1 on FPU assist fault

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>

3 files changed, 31 insertions, 5 deletions

diff --git a/linux-user/hppa/cpu_loop.c b/linux-user/hppa/cpu_loop.c
index 890e758cd1..9abaad5ef8 100644
--- a/linux-user/hppa/cpu_loop.c
+++ b/linux-user/hppa/cpu_loop.c
@@ -112,7 +112,7 @@ static abi_ulong hppa_lws(CPUHPPAState *env)
 void cpu_loop(CPUHPPAState *env)
 {
     CPUState *cs = env_cpu(env);
-    abi_ulong ret;
+    abi_ulong ret, si_code = 0;
     int trapnr;
 
     while (1) {
@@ -169,7 +169,15 @@ void cpu_loop(CPUHPPAState *env)
             force_sig_fault(TARGET_SIGFPE, TARGET_FPE_CONDTRAP, env->iaoq_f);
             break;
         case EXCP_ASSIST:
-            force_sig_fault(TARGET_SIGFPE, 0, env->iaoq_f);
+            #define set_si_code(mask, val) \
+                if (env->fr[0] & mask) { si_code = val; }
+            set_si_code(R_FPSR_FLG_I_MASK, TARGET_FPE_FLTRES);
+            set_si_code(R_FPSR_FLG_U_MASK, TARGET_FPE_FLTUND);
+            set_si_code(R_FPSR_FLG_O_MASK, TARGET_FPE_FLTOVF);
+            set_si_code(R_FPSR_FLG_Z_MASK, TARGET_FPE_FLTDIV);
+            set_si_code(R_FPSR_FLG_V_MASK, TARGET_FPE_FLTINV);
+            #undef set_si_code
+            force_sig_fault(TARGET_SIGFPE, si_code, env->iaoq_f);
             break;
         case EXCP_BREAK:
             force_sig_fault(TARGET_SIGTRAP, TARGET_TRAP_BRKPT, env->iaoq_f);
diff --git a/target/hppa/fpu_helper.c b/target/hppa/fpu_helper.c
index ddd0a343d6..45353202fa 100644
--- a/target/hppa/fpu_helper.c
+++ b/target/hppa/fpu_helper.c
@@ -94,7 +94,8 @@ static void update_fr0_op(CPUHPPAState *env, uintptr_t ra)
 {
     uint32_t soft_exp = get_float_exception_flags(&env->fp_status);
     uint32_t hard_exp = 0;
-    uint32_t shadow = env->fr0_shadow;
+    uint32_t shadow = env->fr0_shadow & 0x3ffffff;
+    uint32_t fr1 = 0;
 
     if (likely(soft_exp == 0)) {
         env->fr[0] = (uint64_t)shadow << 32;
@@ -107,9 +108,22 @@ static void update_fr0_op(CPUHPPAState *env, uintptr_t ra)
     hard_exp |= CONVERT_BIT(soft_exp, float_flag_overflow,  R_FPSR_ENA_O_MASK);
     hard_exp |= CONVERT_BIT(soft_exp, float_flag_divbyzero, R_FPSR_ENA_Z_MASK);
     hard_exp |= CONVERT_BIT(soft_exp, float_flag_invalid,   R_FPSR_ENA_V_MASK);
-    shadow |= hard_exp << (R_FPSR_FLAGS_SHIFT - R_FPSR_ENABLES_SHIFT);
+    if (hard_exp & shadow) {
+        shadow = FIELD_DP32(shadow, FPSR, T, 1);
+        /* fill exception register #1, which is lower 32-bits of fr[0] */
+#if !defined(CONFIG_USER_ONLY)
+        if (hard_exp & (R_FPSR_ENA_O_MASK | R_FPSR_ENA_U_MASK)) {
+            /* over- and underflow both set overflow flag only */
+            fr1 = FIELD_DP32(fr1, FPSR, C, 1);
+            fr1 = FIELD_DP32(fr1, FPSR, FLG_O, 1);
+        } else
+#endif
+        {
+            fr1 |= hard_exp << (R_FPSR_FLAGS_SHIFT - R_FPSR_ENABLES_SHIFT);
+        }
+    }
     env->fr0_shadow = shadow;
-    env->fr[0] = (uint64_t)shadow << 32;
+    env->fr[0] = (uint64_t)shadow << 32 | fr1;
 
     if (hard_exp & shadow) {
         hppa_dynamic_excp(env, EXCP_ASSIST, ra);
diff --git a/target/hppa/int_helper.c b/target/hppa/int_helper.c
index 7d48643bb6..191ae19404 100644
--- a/target/hppa/int_helper.c
+++ b/target/hppa/int_helper.c
@@ -177,6 +177,10 @@ void hppa_cpu_do_interrupt(CPUState *cs)
                     }
                 }
                 env->cr[CR_IIR] = ldl_phys(cs->as, paddr);
+                if (i == EXCP_ASSIST) {
+                    /* stuff insn code into bits of FP exception register #1 */
+                    env->fr[0] |= (env->cr[CR_IIR] & 0x03ffffff);
+                }
             }
             break;