target-xtensa: avoid double-stopping at breakpoints

env->exception_taken is set every time an exception is taken. It is used
to allow single-stepping to stop at the first exception handler
instruction. This however must exclude debug exceptions, as otherwise
first step from the instruction where breakpoint was hit stops at that
same instruction.
Also don't check env->exception_taken directly from the
gen_intermediate_code_internal, instead allocate and use TB flag
XTENSA_TBFLAG_EXCEPTION.

Signed-off-by: Max Filippov <jcmvbkbc@gmail.com>

diff --git a/target-xtensa/cpu.h b/target-xtensa/cpu.h
index a8f02f6e4be092d15da3e629794e806c43001556..95103e9e8787980b48bb089fb40eb706152437e8 100644 (file)
--- a/target-xtensa/cpu.h
+++ b/target-xtensa/cpu.h
@@ -484,6 +484,7 @@ static inline int cpu_mmu_index(CPUXtensaState *env)
 #define XTENSA_TBFLAG_ICOUNT 0x20
 #define XTENSA_TBFLAG_CPENABLE_MASK 0x3fc0
 #define XTENSA_TBFLAG_CPENABLE_SHIFT 6
+#define XTENSA_TBFLAG_EXCEPTION 0x4000
 
 static inline void cpu_get_tb_cpu_state(CPUXtensaState *env, target_ulong *pc,
         target_ulong *cs_base, int *flags)
@@ -510,6 +511,9 @@ static inline void cpu_get_tb_cpu_state(CPUXtensaState *env, target_ulong *pc,
     if (xtensa_option_enabled(env->config, XTENSA_OPTION_COPROCESSOR)) {
         *flags |= env->sregs[CPENABLE] << XTENSA_TBFLAG_CPENABLE_SHIFT;
     }
+    if (ENV_GET_CPU(env)->singlestep_enabled && env->exception_taken) {
+        *flags |= XTENSA_TBFLAG_EXCEPTION;
+    }
 }
 
 #include "exec/cpu-all.h"

diff --git a/target-xtensa/op_helper.c b/target-xtensa/op_helper.c
index 834fe9087debe23c2b4714dcc58f8f0d5c771d8a..6ca912c5bb46d631613e8151883e38ce5dc8ab96 100644 (file)
--- a/target-xtensa/op_helper.c
+++ b/target-xtensa/op_helper.c
@@ -96,6 +96,9 @@ static void tb_invalidate_virtual_addr(CPUXtensaState *env, uint32_t vaddr)
 void HELPER(exception)(CPUXtensaState *env, uint32_t excp)
 {
     env->exception_index = excp;
+    if (excp == EXCP_DEBUG) {
+        env->exception_taken = 0;
+    }
     cpu_loop_exit(env);
 }
 

diff --git a/target-xtensa/translate.c b/target-xtensa/translate.c
index e6923291579fd12c013c61c01b4ead601b88a601..7ea5e2ae168d6fd8c021bdf83b31b92be862d9d9 100644 (file)
--- a/target-xtensa/translate.c
+++ b/target-xtensa/translate.c
@@ -2918,8 +2918,7 @@ void gen_intermediate_code_internal(XtensaCPU *cpu,
 
     gen_tb_start();
 
-    if (cs->singlestep_enabled && env->exception_taken) {
-        env->exception_taken = 0;
+    if (tb->flags & XTENSA_TBFLAG_EXCEPTION) {
         tcg_gen_movi_i32(cpu_pc, dc.pc);
         gen_exception(&dc, EXCP_DEBUG);
     }