Re: [PATCH, ARM] attribute target (thumb,arm) [4/6] respin (4th)

[Ramana Radhakrishnan]

I'm still playing with the code, so this is a partial review.
We should prevent inlining of ARM state functions into functions we know 
will be T16 if !TARGET_SOFT_FLOAT on the grounds that the architecture 
doesn't have floating point instruction encodings in the T16 ISA 
(Thumb1). We'll just cause internal compiler errors if we allow this.


On 07/05/15 00:03, Sandra Loosemore wrote:
On 05/06/2015 08:24 AM, Christian Bruel wrote:
diff '--exclude=.svn' -ruN gnu_trunk.p3/gcc/gcc/doc/extend.texi 
gnu_trunk.p4/gcc/gcc/doc/extend.texi
--- gnu_trunk.p3/gcc/gcc/doc/extend.texi        2015-05-06 09:00:31.232943164 
+0200
+++ gnu_trunk.p4/gcc/gcc/doc/extend.texi        2015-05-06 14:50:05.632612233 
+0200
@@ -3419,6 +3419,25 @@
  the compiler rejects attempts to specify an alternative.
  @end table

+@item target (@var{options})
+@cindex @code{target} function attribute
+As discussed in @ref{Common Function Attributes}, this attribute
+allows specification of target-specific compilation options.
+
+On ARM, the following options are allowed:
+
+@table @samp
+@item thumb
+@cindex @code{target("thumb")} function attribute, ARM
+Force Thumb1 Thumb2 code generation depending on the architecture.

"Force Thumb or Thumb-2 code generation, depending on the architecture."

I'd rather it said something like

"Force code generation in the Thumb (T16/ T32) ISA. The exact 
instructions chosen depends on the architecture levels chosen."

+
+@item arm
+@cindex @code{target("arm")} function attribute, ARM
+Force ARM code generation.

"Force code generation in the ARM (A32) ISA."

+@end table
+
+Functions from different modes can be inlined using the caller mode.

Rewrite this based on the review comment about inlining in the Thumb16 
state from ARM state.

        

"...the caller's mode."

+
  @node AVR Function Attributes
  @subsection AVR Function Attributes

@@ -18436,8 +18455,9 @@
  @xref{Function Attributes}, for more information about the
  @code{target} attribute and the attribute syntax.

-The @code{#pragma GCC target} pragma is presently implemented for
-x86, PowerPC, and Nios II targets only.
+The @code{#pragma GCC target} pragma is implemented for
+ARM, x86, PowerPC, and Nios II targets.
+

I'd rather say this once we have proper support with arch, cpu and fpu 
options enabled. Until such a time I think this hunk is a bit premature.


Ramana