> -----Original Message-----
> From: Steve Ellcey [mailto:sell...@imgtec.com]
> Sent: Friday, October 23, 2015 2:08 PM
> To: Myers, Joseph
> Cc: Bernd Schmidt; Mike Stump; gcc-patches@gcc.gnu.org;
> matthew.fort...@imgtec.com; Moore, Catherine
> Subject: Re: [Patch, MIPS] Frame header optimization for MIPS (part 2)
>
> Just to follow up on this string, here is a new version of the patch
> with the extraneous parenthesis removed.
>
> Steve Ellcey
> sell...@imgtec.com
>
>
> 2015-10-23 Steve Ellcey <sell...@imgtec.com>
>
> * frame-header-opt.c (gate): Check for optimize > 0.
> (has_inlined_assembly): New function.
> (needs_frame_header_p): Remove is_leaf_function check,
> add argument type check.
> (callees_functions_use_frame_header): Add is_leaf_function
> and has_inlined_assembly calls..
> (set_callers_may_not_allocate_frame): New function.
> (frame_header_opt): Add is_leaf_function call, add
> set_callers_may_not_allocate_frame call.
> * config/mips/mips.c (mips_compute_frame_info): Add check
> to see if callee saved regs can be put in frame header.
> (mips_expand_prologue): Add check to see if step1 is zero,
> fix cfa restores when using frame header to store regs.
> (mips_can_use_return_insn): Check to see if registers are
> stored in frame header.
> * config/mips/mips.h (machine_function): Add
> callers_may_not_allocate_frame and
> use_frame_header_for_callee_saved_regs fields.
This is okay after making the minor corrections embedded below.
I'm sorry that it took me so long to review this patch.
Catherine
>
> diff --git a/gcc/config/mips/frame-header-opt.c b/gcc/config/mips/frame-
> header-opt.c
> index 7c7b1f2..2cf589d 100644
> --- a/gcc/config/mips/frame-header-opt.c
> +++ b/gcc/config/mips/frame-header-opt.c
> @@ -125,6 +125,29 @@ is_leaf_function (function *fn)
> return true;
> }
>
> +/* Return true if this function has inline assembly code or if we cannot
> + be certain that it does not. False if know that there is no inline
> + assembly. */
> +
s/False if know/False if we know/
> @@ -136,20 +159,26 @@ needs_frame_header_p (function *fn)
> if (fn->decl == NULL)
> return true;
>
> - if (fn->stdarg || !is_leaf_function (fn))
> + if (fn->stdarg)
> return true;
>
> for (t = DECL_ARGUMENTS (fn->decl); t; t = TREE_CHAIN (t))
> {
> if (!use_register_for_decl (t))
> - return true;
> + return true;
> +
> + /* Some 64 bit types may get copied to general registers using the
> frame
> + header, see mips_output_64bit_xfer. Checking for SImode only may be
> + overly restrictive but it is gauranteed to be safe. */
s/64 bit/64-bit/
s/gauranteed/guaranteed/
> diff --git a/gcc/config/mips/mips.c b/gcc/config/mips/mips.c
> index c5affc8..5a9d48d 100644
> --- a/gcc/config/mips/mips.c
> +++ b/gcc/config/mips/mips.c
> @@ -10465,6 +10465,35 @@ mips_compute_frame_info (void)
> frame->cop0_sp_offset = offset - UNITS_PER_WORD;
> }
>
> + /* Determine if we can save the callee saved registers in the frame
> + header. Restrict this to functions where there is no other reason
> + to allocate stack space so that we can completely eliminate the
> + instructions that modify the stack pointer. */
> +
s/callee saved/callee-saved/
s/completely//
>
>
>
> 2015-10-23 Steve Ellcey <sell...@imgtec.com>
>
> * gcc.target/mips/frame-header-4.c: New test.
>
> diff --git a/gcc/testsuite/gcc.target/mips/frame-header-4.c
> b/gcc/testsuite/gcc.target/mips/frame-header-4.c
> index e69de29..3cddba1 100644
> --- a/gcc/testsuite/gcc.target/mips/frame-header-4.c
> +++ b/gcc/testsuite/gcc.target/mips/frame-header-4.c
> @@ -0,0 +1,20 @@
> +/* Verify that we can optimize away the frame header allocation in bar
> + by having it use its frame header to store $31 in before calling foo. */
> +
> +/* { dg-do compile } */
> +/* { dg-options "-mframe-header-opt -mabi=32" } */
> +/* { dg-skip-if "code quality test" { *-*-* } { "-O0" } { "" } } */
> +/* { dg-final { scan-assembler-not "\taddiu\t\\\$sp" } } */
> +
> +int __attribute__ ((noinline))
> +foo (int a, int b)
> +{
> + return a + b;
> +}
> +
> +int __attribute__ ((noinline))
> +bar (int a, int b)
> +{
> + return 1 + foo(a,b);
> +}
> +
Space after foo, please. Change the two tabs to two space each.
