-Ostrip-constant-names

[xonotic/gmqcc.git] / doc / gmqcc.1

diff --git a/doc/gmqcc.1 b/doc/gmqcc.1
index 8ccc6e08203b825f8177d9269e7cbf252317b5d2..8c30d8d8da05cc57ffa5b92e702b30a03ef84b58 100644 (file)
--- a/doc/gmqcc.1
+++ b/doc/gmqcc.1
@@ -244,10 +244,6 @@ token inside the enclosing attribute-brackets. This may change when
 the actual attribute syntax is better defined.
 .SH COMPILE FLAGS
 .TP
-.B -foverlap-locals
-Allow local variables to overlap with each other if they don't
-interfer with each other. (Not implemented right now)
-.TP
 .B -fdarkplaces-string-table-bug
 Add some additional characters to the string table in order to
 compensate for a wrong boundcheck in some specific version of the
@@ -331,6 +327,46 @@ effectively causes the unary not in strings to use NOT_F instead.
 An empty string is considered to be false everywhere. This means loops
 and if statements which depend on a string will perform a NOT_S
 instruction on the string before using it.
+.TP
+.B -futf8
+Enable utf8 characters. This allows utf-8 encoded character constants,
+and escape sequence codepoints in the valid utf-8 range. Effectively
+enabling escape sequences like '\\{x2211}'.
+.SH OPTIMIZATIONS
+.TP
+.B -Opeephole
+Some general peephole optimizations. For instance the code `a = b + c`
+typically generates 2 instructions, an ADD and a STORE. This
+optimization removes the STORE and lets the ADD write directly into A.
+.TP
+.B -Otail-recursion
+Tail recursive function calls will be turned into loops to avoid the
+overhead of the CALL and RETURN instructions.
+.TP
+.B -Ooverlap-locals
+Make all functions which use neither local arrays nor have locals
+which are seen as possibly uninitialized use the same local section.
+This should be pretty safe compared to other compilers which do not
+check for uninitialized values properly. The problem is that there's
+QC code out there which really doesn't initialize some values. This is
+fine as long as this kind of optimization isn't used, but also, only
+as long as the functions cannot be called in a recursive manner. Since
+it's hard to know whether or not an array is actually fully
+initialized, especially when initializing it via a loop, we assume
+functions with arrays to be too dangerous for this optimization.
+.TP
+.B -Olocal-temps
+This promotes locally declared variables to "temps". Meaning when a
+temporary result of an operation has to be stored somewhere, a local
+variable which is not 'alive' at that point can be used to keep the
+result. This can reduce the size of the global section.
+This will not have declared variables overlap, even if it was
+possible.
+.TP
+.B -Ostrip-constant-names
+Don't generate defs for immediate values or even declared constants.
+Meaning variables which are implicitly constant or qualified as such
+using the 'const' keyword.
 .SH CONFIG
 The configuration file is similar to regular .ini files. Comments
 start with hashtags or semicolons, sections are written in square