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Line up the comments in a code example. 

llvm-svn: 145908
This commit is contained in:
Dan Gohman 2011-12-06 03:31:14 +00:00
parent 9a2a0933ed
commit 5f115a78cb
1 changed files with 19 additions and 19 deletions
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38
llvm/docs/LangRef.html
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@ -2582,11 +2582,11 @@ b: unreachable
<pre class="doc_code">
entry:
%poison = sub nuw i32 0, 1 ; Results in a poison value.
%still_poison = and i32 %poison, 0 ; Whereas (and i32 undef, 0) would return 0.
%still_poison = and i32 %poison, 0 ; Whereas (and i32 undef, 0) would return 0.
%poison_yet_again = getelementptr i32* @h, i32 %still_poison
store i32 0, i32* %poison_yet_again ; undefined behavior
store i32 %poison, i32* @g ; Poison value conceptually stored to memory.
store i32 %poison, i32* @g ; Poison value conceptually stored to memory.
%poison2 = load i32* @g ; Returns a poison value, not just undef.
store volatile i32 %poison, i32* @g ; External observation; undefined behavior.
@ -2596,38 +2596,38 @@ entry:
%poison3 = load i16* %narrowaddr ; Returns a poison value.
%poison4 = load i64* %wideaddr ; Returns a poison value.
%cmp = icmp slt i32 %poison, 0 ; Returns a poison value.
br i1 %cmp, label %true, label %end ; Branch to either destination.
%cmp = icmp slt i32 %poison, 0 ; Returns a poison value.
br i1 %cmp, label %true, label %end ; Branch to either destination.
true:
store volatile i32 0, i32* @g ; This is control-dependent on %cmp, so
; it has undefined behavior.
store volatile i32 0, i32* @g ; This is control-dependent on %cmp, so
; it has undefined behavior.
br label %end
end:
%p = phi i32 [ 0, %entry ], [ 1, %true ]
; Both edges into this PHI are
; control-dependent on %cmp, so this
; always results in a poison value.
; Both edges into this PHI are
; control-dependent on %cmp, so this
; always results in a poison value.
store volatile i32 0, i32* @g ; This would depend on the store in %true
; if %cmp is true, or the store in %entry
; otherwise, so this is undefined behavior.
store volatile i32 0, i32* @g ; This would depend on the store in %true
; if %cmp is true, or the store in %entry
; otherwise, so this is undefined behavior.
br i1 %cmp, label %second_true, label %second_end
; The same branch again, but this time the
; true block doesn't have side effects.
; The same branch again, but this time the
; true block doesn't have side effects.
second_true:
; No side effects!
ret void
second_end:
store volatile i32 0, i32* @g ; This time, the instruction always depends
; on the store in %end. Also, it is
; control-equivalent to %end, so this is
; well-defined (again, ignoring earlier
; undefined behavior in this example).
store volatile i32 0, i32* @g ; This time, the instruction always depends
; on the store in %end. Also, it is
; control-equivalent to %end, so this is
; well-defined (again, ignoring earlier
; undefined behavior in this example).
</pre>
</div>