wingo pushed a commit to branch lightning
in repository guile.
commit 36a3ae90588d70aca202dfd9fe5a029560e34709
Author: Paolo Bonzini <[email protected]>
Date: Thu Nov 23 09:06:07 2006 +0000
refine ludovic's doc patch
git-archimport-id: [email protected]/lightning--stable--1.2--patch-51
---
doc/using.texi | 20 ++++++++++++--------
1 file changed, 12 insertions(+), 8 deletions(-)
diff --git a/doc/using.texi b/doc/using.texi
index 173f1e7..332383e 100644
--- a/doc/using.texi
+++ b/doc/using.texi
@@ -100,20 +100,24 @@ preserved across function calls (@code{V0}, @code{V1} and
@code{R2}). Six registers are not very much, but this
restriction was forced by the need to target CISC architectures
which, like the x86, are poor of registers; anyway, backends can
-specify the actual number of available caller- and callee-save
-registers with the macros @code{JIT_R_NUM} and @code{JIT_V_NUM}.
+specify the actual number of available registers with the macros
+@code{JIT_R_NUM} (for caller-save registers) and @code{JIT_V_NUM}
+(for callee-save registers).
-In addition, there is a special @code{RET} register which contains the
-return value of the current function (@emph{not} the return value of
-callees---use the @code{retval} instruction for this). You should
+In addition, there is a special @code{RET} register which contains
+the return value of the current function (@emph{not} the return value
+of callees---use the @code{retval} instruction for this). You should
always remember, however, that writing this register could overwrite
either a general-purpose register or an incoming parameter, depending
on the architecture.
There are at least six floating-point registers, named @code{FPR0} to
-@code{FPR5}. These are separate from the integer registers on
-all the supported architectures; on Intel architectures, the
-register stack is mapped to a flat register file.
+@code{FPR5}. These are caller-save and are separate from the integer
+registers on all the supported architectures; on Intel architectures,
+the register stack is mapped to a flat register file. As for the
+integer registers, the macro @code{JIT_FPR_NUM} yields the number of
+floating-point registers, and the special @code{FPRET} register contains
+the return value of the current function.
The complete instruction set follows; as you can see, most non-memory
operations only take integers, long integers (either signed or
