From: Andrew Pinski <quic_apinski@quicinc.com>
To: <gcc-patches@gcc.gnu.org>
Cc: Andrew Pinski <quic_apinski@quicinc.com>
Subject: [PATCH] Mention that some options are turned on by `-Ofast` in their descriptions [PR97263]
Date: Mon, 6 May 2024 14:27:01 -0700 [thread overview]
Message-ID: <20240506212701.4115576-1-quic_apinski@quicinc.com> (raw)
Like was done for -ffast-math in r0-105946-ga570fc16fa8056, we should
document that -Ofast enables -fmath-errno, -funsafe-math-optimizations,
-finite-math-only, -fno-trapping-math in their documentation.
Note this changes the stronger "must not" to be "is not" for -fno-trapping-math
since we do enable it for -Ofast already.
OK?
gcc/ChangeLog:
PR middle-end/97263
* doc/invoke.texi(fmath-errno): Document it is turned on
with -Ofast.
(funsafe-math-optimizations): Likewise.
(ffinite-math-only): Likewise.
(fno-trapping-math): Likewise and use less strong language.
Signed-off-by: Andrew Pinski <quic_apinski@quicinc.com>
---
gcc/doc/invoke.texi | 41 ++++++++++++++++++++++-------------------
1 file changed, 22 insertions(+), 19 deletions(-)
diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
index 9456ced468a..14ff4d25da7 100644
--- a/gcc/doc/invoke.texi
+++ b/gcc/doc/invoke.texi
@@ -14996,11 +14996,12 @@ with a single instruction, e.g., @code{sqrt}. A program that relies on
IEEE exceptions for math error handling may want to use this flag
for speed while maintaining IEEE arithmetic compatibility.
-This option is not turned on by any @option{-O} option since
-it can result in incorrect output for programs that depend on
-an exact implementation of IEEE or ISO rules/specifications for
-math functions. It may, however, yield faster code for programs
-that do not require the guarantees of these specifications.
+This option is not turned on by any @option{-O} option besides
+@option{-Ofast} since it can result in incorrect output for
+programs that depend on an exact implementation of IEEE or
+ISO rules/specifications for math functions. It may, however,
+yield faster code for programs that do not require the guarantees
+of these specifications.
The default is @option{-fmath-errno}.
@@ -15017,11 +15018,12 @@ ANSI standards. When used at link time, it may include libraries
or startup files that change the default FPU control word or other
similar optimizations.
-This option is not turned on by any @option{-O} option since
-it can result in incorrect output for programs that depend on
-an exact implementation of IEEE or ISO rules/specifications for
-math functions. It may, however, yield faster code for programs
-that do not require the guarantees of these specifications.
+This option is not turned on by any @option{-O} option besides
+@option{-Ofast} since it can result in incorrect output
+for programs that depend on an exact implementation of IEEE
+or ISO rules/specifications for math functions. It may, however,
+yield faster code for programs that do not require the guarantees
+of these specifications.
Enables @option{-fno-signed-zeros}, @option{-fno-trapping-math},
@option{-fassociative-math} and @option{-freciprocal-math}.
@@ -15061,11 +15063,12 @@ The default is @option{-fno-reciprocal-math}.
Allow optimizations for floating-point arithmetic that assume
that arguments and results are not NaNs or +-Infs.
-This option is not turned on by any @option{-O} option since
-it can result in incorrect output for programs that depend on
-an exact implementation of IEEE or ISO rules/specifications for
-math functions. It may, however, yield faster code for programs
-that do not require the guarantees of these specifications.
+This option is not turned on by any @option{-O} option besides
+@option{-Ofast} since it can result in incorrect output
+for programs that depend on an exact implementation of IEEE or
+ISO rules/specifications for math functions. It may, however,
+yield faster code for programs that do not require the guarantees
+of these specifications.
The default is @option{-fno-finite-math-only}.
@@ -15089,10 +15092,10 @@ underflow, inexact result and invalid operation. This option requires
that @option{-fno-signaling-nans} be in effect. Setting this option may
allow faster code if one relies on ``non-stop'' IEEE arithmetic, for example.
-This option should never be turned on by any @option{-O} option since
-it can result in incorrect output for programs that depend on
-an exact implementation of IEEE or ISO rules/specifications for
-math functions.
+This option is not turned on by any @option{-O} option besides
+@option{-Ofast} since it can result in incorrect output for programs
+that depend on an exact implementation of IEEE or ISO rules/specifications
+for math functions.
The default is @option{-ftrapping-math}.
--
2.43.0
next reply other threads:[~2024-05-06 21:27 UTC|newest]
Thread overview: 2+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-05-06 21:27 Andrew Pinski [this message]
2024-05-07 6:34 ` Richard Biener
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