[PATCH-for-5.0] gdbstub: Introduce gdb_get_freg32() to get float32 registers

[PATCH-for-5.0] gdbstub: Introduce gdb_get_freg32() to get float32 registers

[Philippe Mathieu-Daudé]

Since we now use a GByteArray, we can not use stfl_p() directly.
Introduce the gdb_get_freg32() helper to load a float32 register.

Fixes: a010bdbe719 ("extend GByteArray to read register helpers")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
Based-on: <20200414102427.7459-1-philmd@redhat.com>
---
 include/exec/gdbstub.h | 12 ++++++++++++
 target/sh4/gdbstub.c   |  6 ++----
 2 files changed, 14 insertions(+), 4 deletions(-)

diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index b52d9933ee..52a4a936c6 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -125,6 +125,18 @@ static inline int gdb_get_reg128(GByteArray *buf, uint64_t val_hi,
     return 16;
 }
 
+static inline int gdb_get_freg32(GByteArray *array, float32 val)
+{
+    uint8_t buf[4];
+
+    QEMU_BUILD_BUG_ON(sizeof(CPU_FloatU) != sizeof(buf));
+
+    stfl_p(buf, val);
+    g_byte_array_append(array, buf, sizeof(buf));
+
+    return sizeof(buf);
+}
+
 static inline int gdb_get_zeroes(GByteArray *array, size_t len)
 {
     for (size_t i = 0; i < len; i++) {
diff --git a/target/sh4/gdbstub.c b/target/sh4/gdbstub.c
index 49fc4a0cc6..da95205889 100644
--- a/target/sh4/gdbstub.c
+++ b/target/sh4/gdbstub.c
@@ -58,11 +58,9 @@ int superh_cpu_gdb_read_register(CPUState *cs, GByteArray *mem_buf, int n)
         return gdb_get_regl(mem_buf, env->fpscr);
     case 25 ... 40:
         if (env->fpscr & FPSCR_FR) {
-            stfl_p(mem_buf, env->fregs[n - 9]);
-        } else {
-            stfl_p(mem_buf, env->fregs[n - 25]);
+            return gdb_get_freg32(mem_buf, env->fregs[n - 9]);
         }
-        return 4;
+        return gdb_get_freg32(mem_buf, env->fregs[n - 25]);
     case 41:
         return gdb_get_regl(mem_buf, env->ssr);
     case 42:
-- 
2.21.1

Re: [PATCH-for-5.0] gdbstub: Introduce gdb_get_freg32() to get float32 registers

[Richard Henderson]

On 4/14/20 4:18 AM, Philippe Mathieu-Daudé wrote:
> +static inline int gdb_get_freg32(GByteArray *array, float32 val)
> +{
> +    uint8_t buf[4];
> +
> +    QEMU_BUILD_BUG_ON(sizeof(CPU_FloatU) != sizeof(buf));

Why bother withe the BUG_ON when you could just put the sizeof(CPU_FloatU) into
the array bounds above?


r~

Re: [PATCH-for-5.0] gdbstub: Introduce gdb_get_freg32() to get float32 registers

[Philippe Mathieu-Daudé]

On 4/14/20 5:19 PM, Richard Henderson wrote:
> On 4/14/20 4:18 AM, Philippe Mathieu-Daudé wrote:
>> +static inline int gdb_get_freg32(GByteArray *array, float32 val)
>> +{
>> +    uint8_t buf[4];
>> +
>> +    QEMU_BUILD_BUG_ON(sizeof(CPU_FloatU) != sizeof(buf));
> 
> Why bother withe the BUG_ON when you could just put the sizeof(CPU_FloatU) into
> the array bounds above?

Ah good idea, thanks :)

> 
> 
> r~
>