doc: Update -falign-functions/-falign-loops/-falign-jumps

Message ID 20200328213414.14811-1-hjl.tools@gmail.com
State New
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  • doc: Update -falign-functions/-falign-loops/-falign-jumps
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Commit Message

Marek Polacek via Gcc-patches March 28, 2020, 9:34 p.m.
Change -falign-functions=N to

    Align the start of functions to the next power-of-two greater than
    or equal to N.

Add

    If '-falign-labels' is greater than this value, then its value is
    used instead.

to -falign-loops=N and -falign-jumps=N.

OK for master?

H.J.
--
	PR driver/94381
	* doc/invoke.texi: Update -falign-functions, -falign-loops and
	-falign-jumps documentation.
---
 gcc/doc/invoke.texi | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

-- 
2.25.1

Comments

Sandra Loosemore March 29, 2020, 10:04 p.m. | #1
On 3/28/20 3:34 PM, H.J. Lu via Gcc-patches wrote:
> Change -falign-functions=N to

> 

>      Align the start of functions to the next power-of-two greater than

>      or equal to N.

> 

> Add

> 

>      If '-falign-labels' is greater than this value, then its value is

>      used instead.

> 

> to -falign-loops=N and -falign-jumps=N.

> 

> OK for master?

> 

> H.J.

> --

> 	PR driver/94381

> 	* doc/invoke.texi: Update -falign-functions, -falign-loops and

> 	-falign-jumps documentation.


OK.

-Sandra

Patch

diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index c2053a3804f..412750c1fc9 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -10939,9 +10939,9 @@  The @option{-fstrict-aliasing} option is enabled at levels
 @itemx -falign-functions=@var{n}:@var{m}:@var{n2}
 @itemx -falign-functions=@var{n}:@var{m}:@var{n2}:@var{m2}
 @opindex falign-functions
-Align the start of functions to the next power-of-two greater than
-@var{n}, skipping up to @var{m}-1 bytes.  This ensures that at least
-the first @var{m} bytes of the function can be fetched by the CPU
+Align the start of functions to the next power-of-two greater than or
+equal to @var{n}, skipping up to @var{m}-1 bytes.  This ensures that at
+least the first @var{m} bytes of the function can be fetched by the CPU
 without crossing an @var{n}-byte alignment boundary.
 
 If @var{m} is not specified, it defaults to @var{n}.
@@ -11007,6 +11007,9 @@  Align loops to a power-of-two boundary.  If the loops are executed
 many times, this makes up for any execution of the dummy padding
 instructions.
 
+If @option{-falign-labels} is greater than this value, then its value
+is used instead.
+
 Parameters of this option are analogous to the @option{-falign-functions} option.
 @option{-fno-align-loops} and @option{-falign-loops=1} are
 equivalent and mean that loops are not aligned.
@@ -11026,6 +11029,9 @@  Align branch targets to a power-of-two boundary, for branch targets
 where the targets can only be reached by jumping.  In this case,
 no dummy operations need be executed.
 
+If @option{-falign-labels} is greater than this value, then its value
+is used instead.
+
 Parameters of this option are analogous to the @option{-falign-functions} option.
 @option{-fno-align-jumps} and @option{-falign-jumps=1} are
 equivalent and mean that loops are not aligned.