[binutils-gdb] Restrict alpha_convert_register_p

[Yao Qi <qiyao at sourceware dot org>]

https://sourceware.org/git/gitweb.cgi?p=binutils-gdb.git;h=68fce50f04f495980f4ea81746339a9de5b52ebb

commit 68fce50f04f495980f4ea81746339a9de5b52ebb
Author: Yao Qi <yao.qi@linaro.org>
Date:   Wed May 24 22:15:23 2017 +0100

    Restrict alpha_convert_register_p
    
    This patch restricts alpha_convert_register_p from
    "TYPE_LENGTH (type) != 8" to "TYPE_LENGTH (type) == 4", because,
    
     - we have check "TYPE_LENGTH (valtype) == 4" in alpha_register_to_value
       and alpha_value_to_register,
     - alpha lds and sts instruction access 4 bytes,
     - comments "It might need to convert the [float] register into the
       corresponding [integer] type (see Alpha)" and integer is 4-byte on
       alpha,
    
    I think it is the right restrict condition to "TYPE_LENGTH (valtype) == 4".
    
    gdb:
    
    2017-05-24  Yao Qi  <yao.qi@linaro.org>
    
    	* alpha-tdep.c (alpha_convert_register_p): Return true if type
    	length is 4.
    	(alpha_register_to_value): Remove type length check.
    	(alpha_value_to_register): Likewise.

Diff:
---
 gdb/ChangeLog    |  7 +++++++
 gdb/alpha-tdep.c | 27 +++++++++------------------
 2 files changed, 16 insertions(+), 18 deletions(-)

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 0cb8e36..1234e14 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,12 @@
 2017-05-24  Yao Qi  <yao.qi@linaro.org>
 
+	* alpha-tdep.c (alpha_convert_register_p): Return true if type
+	length is 4.
+	(alpha_register_to_value): Remove type length check.
+	(alpha_value_to_register): Likewise.
+
+2017-05-24  Yao Qi  <yao.qi@linaro.org>
+
 	* ia64-tdep.c (ia64_convert_register_p): Check type's code is
 	TYPE_CODE_FLT.
 
diff --git a/gdb/alpha-tdep.c b/gdb/alpha-tdep.c
index 672e578..d7cc0f4 100644
--- a/gdb/alpha-tdep.c
+++ b/gdb/alpha-tdep.c
@@ -227,7 +227,7 @@ alpha_sts (struct gdbarch *gdbarch, void *out, const void *in)
 /* The alpha needs a conversion between register and memory format if the
    register is a floating point register and memory format is float, as the
    register format must be double or memory format is an integer with 4
-   bytes or less, as the representation of integers in floating point
+   bytes, as the representation of integers in floating point
    registers is different.  */
 
 static int
@@ -235,7 +235,7 @@ alpha_convert_register_p (struct gdbarch *gdbarch, int regno,
 			  struct type *type)
 {
   return (regno >= ALPHA_FP0_REGNUM && regno < ALPHA_FP0_REGNUM + 31
-	  && TYPE_LENGTH (type) != 8);
+	  && TYPE_LENGTH (type) == 4);
 }
 
 static int
@@ -252,14 +252,10 @@ alpha_register_to_value (struct frame_info *frame, int regnum,
 				 in, optimizedp, unavailablep))
     return 0;
 
-  if (TYPE_LENGTH (valtype) == 4)
-    {
-      alpha_sts (gdbarch, out, in);
-      *optimizedp = *unavailablep = 0;
-      return 1;
-    }
-
-  error (_("Cannot retrieve value from floating point register"));
+  gdb_assert (TYPE_LENGTH (valtype) == 4);
+  alpha_sts (gdbarch, out, in);
+  *optimizedp = *unavailablep = 0;
+  return 1;
 }
 
 static void
@@ -268,14 +264,9 @@ alpha_value_to_register (struct frame_info *frame, int regnum,
 {
   gdb_byte out[MAX_REGISTER_SIZE];
 
-  switch (TYPE_LENGTH (valtype))
-    {
-    case 4:
-      alpha_lds (get_frame_arch (frame), out, in);
-      break;
-    default:
-      error (_("Cannot store value in floating point register"));
-    }
+  gdb_assert (TYPE_LENGTH (valtype) == 4);
+  alpha_lds (get_frame_arch (frame), out, in);
+
   put_frame_register (frame, regnum, out);
 }