Re: [PATCH] Change how "print/x" displays floating-point value

[Andreas Schwab <schwab@linux-m68k.org>]

On Feb 18 2022, Tom Tromey via Gdb-patches wrote:

> diff --git a/gdb/NEWS b/gdb/NEWS
> index 9da74e71796..544efa3fe74 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -97,6 +97,12 @@ show style disassembler enabled
>  
>  * Changed commands
>  
> +print
> +  Printing of floating-point values with base-modifying formats like
> +  /x has been changed to display the underlying bytes of the value in
> +  the desired base.  This was GDB's documented behavior, but was never
> +  implemented correctly.

How does that handle padding?

> diff --git a/gdb/testsuite/gdb.base/printcmds.exp b/gdb/testsuite/gdb.base/printcmds.exp
> index 37632985a07..78a2147017d 100644
> --- a/gdb/testsuite/gdb.base/printcmds.exp
> +++ b/gdb/testsuite/gdb.base/printcmds.exp
> @@ -158,8 +158,14 @@ proc test_float_rejected {} {
>  # Regression test for PR gdb/21675
>  proc test_radices {} {
>      gdb_test "print/o 16777211" " = 077777773"
> -    gdb_test "print/d 1.5" " = 1"
> -    gdb_test "print/u 1.5" " = 1"
> +
> +    # See PR gdb/16242 for this.
> +    gdb_test "print/d 1.5f" " = 1069547520"
> +    gdb_test "print/u 1.5f" " = 1069547520"
> +    gdb_test "print/x 1.5f" " = 0x3fc00000"
> +    gdb_test "print/t 1.5f" " = 111111110000000000000000000000"
> +    gdb_test "print/o 1.5f" " = 07760000000"

That assumes a particular representation of the float type that depends
on the target.

-- 
Andreas Schwab, schwab@linux-m68k.org
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