godzil/tack
1
0
Fork 0
Code Issues Pull Requests Actions Packages Projects Releases Wiki Activity

Made to work with troff

Browse Source
This commit is contained in:
ceriel
1990-06-20 10:05:22 +00:00
parent 955002df6c
commit d3a17633aa
25 changed files with 583 additions and 456 deletions
Download Patch File Download Diff File Expand all files Collapse all files

60
doc/ego/cs/cs4
View File

@@ -26,26 +26,26 @@ There are groups for all sorts of operators:
unary, binary, and ternary.
The groups of operators are further partitioned according to the size
of their operand(s) and result.
\" .PP
\" The distinction between operators and expensive loads is not always clear.
\" The ADP instruction for example,
\" might seem a unary operator because it pops one item
\" (a pointer) from the stack.
\" However, two ADP-instructions which pop an item with the same value number
\" need not have the same result,
\" because the attributes (an offset, to be added to the pointer)
\" can be different.
\" Is it then a binary operator?
\" That would give rise to the strange, and undesirable,
\" situation that some binary operators pop two operands
\" and others pop one.
\" The conclusion is inevitable:
\" we have been fooled by the name (ADd Pointer).
\" The ADP-instruction is an expensive load.
\" In this context LAF, meaning Load Address of oFfsetted,
\" would have been a better name,
\" corresponding to LOF, like LAL,
\" Load Address of Local, corresponds to LOL.
.\" .PP
.\" The distinction between operators and expensive loads is not always clear.
.\" The ADP instruction for example,
.\" might seem a unary operator because it pops one item
.\" (a pointer) from the stack.
.\" However, two ADP-instructions which pop an item with the same value number
.\" need not have the same result,
.\" because the attributes (an offset, to be added to the pointer)
.\" can be different.
.\" Is it then a binary operator?
.\" That would give rise to the strange, and undesirable,
.\" situation that some binary operators pop two operands
.\" and others pop one.
.\" The conclusion is inevitable:
.\" we have been fooled by the name (ADd Pointer).
.\" The ADP-instruction is an expensive load.
.\" In this context LAF, meaning Load Address of oFfsetted,
.\" would have been a better name,
.\" corresponding to LOF, like LAL,
.\" Load Address of Local, corresponds to LOL.
.PP
There are groups for all sorts of stores:
direct, indirect, array element.
@@ -91,10 +91,13 @@ because EM expressions are postfix.
When we find an instruction to load an operand,
we load on the fake-stack a struct with the following information:
.DS
(1) the value number of the operand
(2) the size of the operand
(3) a pointer to the first line of EM-code
that constitutes the operand
.TS
l l.
(1) the value number of the operand
(2) the size of the operand
(3) a pointer to the first line of EM-code
that constitutes the operand
.TE
.DE
In most cases, (3) will point to the line
that loaded the operand (e.g. LOL, LOC),
@@ -121,9 +124,12 @@ a recurrence of this expression.
Not only will the operand(s) be popped from the fake-stack,
but the following will be pushed:
.DS
(1) the value number of the result
(2) the size of the result
(3) a pointer to the first line of the expression
.TS
l l.
(1) the value number of the result
(2) the size of the result
(3) a pointer to the first line of the expression
.TE
.DE
In this way an item on the fake-stack always contains
the necessary information.