diff options
| -rw-r--r-- | gdb/doc/gdb.texinfo | 33 |
1 files changed, 17 insertions, 16 deletions
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo index 89090e9..264aaeb 100644 --- a/gdb/doc/gdb.texinfo +++ b/gdb/doc/gdb.texinfo @@ -3928,8 +3928,13 @@ may be any register name valid on the machine you are using, with or without the initial @samp{$}. @end table -The register names @code{$pc} and @code{$sp} are used on most machines -for the program counter register and the stack pointer. For example, +_GDBN__ has four ``standard'' register names that are available (in +expressions) on most machines---whenever they don't conflict with an +architecture's canonical mnemonics for registers. The register names +@code{$pc} and @code{$sp} are used for the program counter register and +the stack pointer. @code{$fp} is used for a register that contains a +pointer to the current stack frame, and @code{$ps} is used for a +register that contains the processor status. For example, you could print the program counter in hex with @example p/x $pc @@ -3942,24 +3947,20 @@ x/i $pc @end example @noindent -or add four to the stack pointer with +or add four to the stack pointer @footnote{This is a way of removing one +word from the stack, on machines where stacks grow downward in memory +(most machines, nowadays). This assumes that the innermost stack frame +is selected; setting @code{$sp} is not allowed when other stack frames +are selected. To pop entire frames off the stack, regardless of +machine architecture, use @code{return}; @pxref{Returning}.} with @example set $sp += 4 @end example -@noindent -The last is a way of removing one word from the stack, on machines where -stacks grow downward in memory (most machines, nowadays). This assumes -that the innermost stack frame is selected; setting @code{$sp} is -not allowed when other stack frames are selected. (To pop entire frames -off the stack, regardless of machine architecture, use @code{return}; -@pxref{Returning}.) - -Often @code{$fp} is used for a register that contains a pointer to the -current stack frame, and @code{$ps} is sometimes used for a register -that contains the processor status. These standard register names may -be available on your machine even though the @code{info registers} -command shows other names. For example, on the SPARC, @code{info +Whenever possible, these four standard register names are available on +your machine even though the machine has different canonical mnemonics, +so long as there is no conflict. The @code{info registers} command +shows the canonical names. For example, on the SPARC, @code{info registers} displays the processor status register as @code{$psr} but you can also refer to it as @code{$ps}. |