From 71f9914855ca20169b7e475b14e26fef9b69bbb4 Mon Sep 17 00:00:00 2001 From: Janis Johnson Date: Tue, 29 Oct 2002 16:35:04 +0000 Subject: [PATCH] invoke.texi (-profile-arcs): Remove references to -a and -ax. 2002-10-29 Janis Johnson * doc/invoke.texi (-profile-arcs): Remove references to -a and -ax. From-SVN: r58626 --- gcc/ChangeLog | 4 ++++ gcc/doc/invoke.texi | 18 +----------------- 2 files changed, 5 insertions(+), 17 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 33b313ff3fa0..928a9874ec55 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,7 @@ +2002-10-29 Janis Johnson + + * doc/invoke.texi (-profile-arcs): Remove references to -a and -ax. + 2002-10-29 Eric Botcazou * expr.c (expand_expr) [PLUS]: Don't use simplify_binary_operation; diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi index 10ced6b06b98..0b527b2598f0 100644 --- a/gcc/doc/invoke.texi +++ b/gcc/doc/invoke.texi @@ -2933,18 +2933,7 @@ optimization and code generation options plus Control Optimization}). The other use of @option{-fprofile-arcs} is for use with @code{gcov}, -when it is used with the @option{-ftest-coverage} option. GCC -supports two methods of determining code coverage: the options that -support @code{gcov}, and options @option{-a} and @option{-ax}, which -write information to text files. The options that support @code{gcov} -do not need to instrument every arc in the program, so a program compiled -with them runs faster than a program compiled with @option{-a}, which -adds instrumentation code to every basic block in the program. The -tradeoff: since @code{gcov} does not have execution counts for all -branches, it must start with the execution counts for the instrumented -branches, and then iterate over the program flow graph until the entire -graph has been solved. Hence, @code{gcov} runs a little more slowly than -a program which uses information from @option{-a} and @option{-ax}. +when it is used with the @option{-ftest-coverage} option. With @option{-fprofile-arcs}, for each function of your program GCC creates a program flow graph, then finds a spanning tree for the graph. @@ -2954,11 +2943,6 @@ executed. When an arc is the only exit or only entrance to a block, the instrumentation code can be added to the block; otherwise, a new basic block must be created to hold the instrumentation code. -This option makes it possible to estimate branch probabilities and to -calculate basic block execution counts. In general, basic block -execution counts as provided by @option{-a} do not give enough -information to estimate all branch probabilities. - @need 2000 @item -ftest-coverage @opindex ftest-coverage -- 2.47.2