[PATCH-for-5.0 v2 0/2] gdbstub: Introduce gdb_get_float32/gdb_get_float64 helpers

[PATCH-for-5.0 v2 0/2] gdbstub: Introduce gdb_get_float32/gdb_get_float64 helpers

[Philippe Mathieu-Daudé]

Fixes for GByteArray (commits 462474d760c & a010bdbe719).

Based-on: <20200414102427.7459-1-philmd@redhat.com>
Supersedes: <20200414111846.27495-1-philmd@redhat.com>

Philippe Mathieu-Daudé (2):
  gdbstub: Introduce gdb_get_float32() to get 32-bit float registers
  gdbstub: Introduce gdb_get_float64() to get 64-bit float registers

 include/exec/gdbstub.h          | 24 ++++++++++++++++++++++++
 target/m68k/helper.c            |  3 ++-
 target/ppc/gdbstub.c            |  4 ++--
 target/ppc/translate_init.inc.c |  2 +-
 target/sh4/gdbstub.c            |  6 ++----
 5 files changed, 31 insertions(+), 8 deletions(-)

-- 
2.21.1

[PATCH-for-5.0 v2 1/2] gdbstub: Introduce gdb_get_float32() to get 32-bit float registers

[Philippe Mathieu-Daudé]

Since we now use a GByteArray, we can not use stfl_p() directly.
Introduce the gdb_get_float32() helper to load a float32 register.

Fixes: a010bdbe719 ("extend GByteArray to read register helpers")
Signed-off-by: Philippe Mathieu-Daudé <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..3caca99416 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_float32(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..34ad3ca050 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_float32(mem_buf, env->fregs[n - 9]);
         }
-        return 4;
+        return gdb_get_float32(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 v2 1/2] gdbstub: Introduce gdb_get_float32() to get 32-bit float registers

[Richard Henderson]

On 4/14/20 7:32 AM, Philippe Mathieu-Daudé wrote:
> Since we now use a GByteArray, we can not use stfl_p() directly.
> Introduce the gdb_get_float32() helper to load a float32 register.
> 
> Fixes: a010bdbe719 ("extend GByteArray to read register helpers")
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  include/exec/gdbstub.h | 12 ++++++++++++
>  target/sh4/gdbstub.c   |  6 ++----
>  2 files changed, 14 insertions(+), 4 deletions(-)

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>


r~

[PATCH-for-5.0 v2 2/2] gdbstub: Introduce gdb_get_float64() to get 64-bit float registers

[Philippe Mathieu-Daudé]

When converted to use GByteArray in commits 462474d760c and
a010bdbe719, the call to stfq_p() was removed. This call
serialize a float.
Since we now use a GByteArray, we can not use stfq_p() directly.
Introduce the gdb_get_float64() helper to load a float64 register.

Fixes: 462474d760c ("target/m68k: use gdb_get_reg helpers")
Fixes: a010bdbe719 ("extend GByteArray to read register helpers")
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 include/exec/gdbstub.h          | 12 ++++++++++++
 target/m68k/helper.c            |  3 ++-
 target/ppc/gdbstub.c            |  4 ++--
 target/ppc/translate_init.inc.c |  2 +-
 4 files changed, 17 insertions(+), 4 deletions(-)

diff --git a/include/exec/gdbstub.h b/include/exec/gdbstub.h
index 3caca99416..ef88cefbf6 100644
--- a/include/exec/gdbstub.h
+++ b/include/exec/gdbstub.h
@@ -137,6 +137,18 @@ static inline int gdb_get_float32(GByteArray *array, float32 val)
     return sizeof(buf);
 }
 
+static inline int gdb_get_float64(GByteArray *array, float64 val)
+{
+    uint8_t buf[8];
+
+    QEMU_BUILD_BUG_ON(sizeof(CPU_DoubleU) != sizeof(buf));
+
+    stfq_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/m68k/helper.c b/target/m68k/helper.c
index 014657c637..cc80b48dda 100644
--- a/target/m68k/helper.c
+++ b/target/m68k/helper.c
@@ -72,7 +72,8 @@ static int cf_fpu_gdb_get_reg(CPUM68KState *env, GByteArray *mem_buf, int n)
 {
     if (n < 8) {
         float_status s;
-        return gdb_get_reg64(mem_buf, floatx80_to_float64(env->fregs[n].d, &s));
+        return gdb_get_float64(mem_buf,
+                               floatx80_to_float64(env->fregs[n].d, &s));
     }
     switch (n) {
     case 8: /* fpcontrol */
diff --git a/target/ppc/gdbstub.c b/target/ppc/gdbstub.c
index eb362dd9ae..5c11c88b2a 100644
--- a/target/ppc/gdbstub.c
+++ b/target/ppc/gdbstub.c
@@ -130,7 +130,7 @@ int ppc_cpu_gdb_read_register(CPUState *cs, GByteArray *buf, int n)
         gdb_get_regl(buf, env->gpr[n]);
     } else if (n < 64) {
         /* fprs */
-        gdb_get_reg64(buf, *cpu_fpr_ptr(env, n - 32));
+        gdb_get_float64(buf, *cpu_fpr_ptr(env, n - 32));
     } else {
         switch (n) {
         case 64:
@@ -184,7 +184,7 @@ int ppc_cpu_gdb_read_register_apple(CPUState *cs, GByteArray *buf, int n)
         gdb_get_reg64(buf, env->gpr[n]);
     } else if (n < 64) {
         /* fprs */
-        gdb_get_reg64(buf, *cpu_fpr_ptr(env, n - 32));
+        gdb_get_float64(buf, *cpu_fpr_ptr(env, n - 32));
     } else if (n < 96) {
         /* Altivec */
         gdb_get_reg64(buf, n - 64);
diff --git a/target/ppc/translate_init.inc.c b/target/ppc/translate_init.inc.c
index e853164a86..d825cb5975 100644
--- a/target/ppc/translate_init.inc.c
+++ b/target/ppc/translate_init.inc.c
@@ -9881,7 +9881,7 @@ static int gdb_get_float_reg(CPUPPCState *env, GByteArray *buf, int n)
 {
     uint8_t *mem_buf;
     if (n < 32) {
-        gdb_get_reg64(buf, *cpu_fpr_ptr(env, n));
+        gdb_get_float64(buf, *cpu_fpr_ptr(env, n));
         mem_buf = gdb_get_reg_ptr(buf, 8);
         ppc_maybe_bswap_register(env, mem_buf, 8);
         return 8;
-- 
2.21.1

Re: [PATCH-for-5.0 v2 2/2] gdbstub: Introduce gdb_get_float64() to get 64-bit float registers

[Richard Henderson]

On 4/14/20 7:32 AM, Philippe Mathieu-Daudé wrote:
> When converted to use GByteArray in commits 462474d760c and
> a010bdbe719, the call to stfq_p() was removed. This call
> serialize a float.
> Since we now use a GByteArray, we can not use stfq_p() directly.
> Introduce the gdb_get_float64() helper to load a float64 register.
> 
> Fixes: 462474d760c ("target/m68k: use gdb_get_reg helpers")
> Fixes: a010bdbe719 ("extend GByteArray to read register helpers")
> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  include/exec/gdbstub.h          | 12 ++++++++++++
>  target/m68k/helper.c            |  3 ++-
>  target/ppc/gdbstub.c            |  4 ++--
>  target/ppc/translate_init.inc.c |  2 +-
>  4 files changed, 17 insertions(+), 4 deletions(-)

This one can wait for 5.1, or be dropped altogether, depending.

In this case, we're only making the artificial distinction between float64 and
uint64_t.  Therefore all of the existing uses of gdb_get_reg64 that you replace
are not bug fixes.  Therefore, not 5.0 material.

I've been considering removing float32 and float64, and just replacing them
with uint32_t and uint64_t, and removing all of the associated shims like
stfq_p.  But I've never quite gotten around to doing that.


r~