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Post-review changes on conversion instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@31607 91177308-0d34-0410-b5e6-96231b3b80d8
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Reid Spencer
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@ -120,10 +120,10 @@
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<li><a href="#i_sext">'<tt>sext .. to</tt>' Instruction</a></li>
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<li><a href="#i_fptrunc">'<tt>fptrunc .. to</tt>' Instruction</a></li>
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<li><a href="#i_fpext">'<tt>fpext .. to</tt>' Instruction</a></li>
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<li><a href="#i_fp2uint">'<tt>fp2uint .. to</tt>' Instruction</a></li>
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<li><a href="#i_fp2sint">'<tt>fp2sint .. to</tt>' Instruction</a></li>
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<li><a href="#i_uint2fp">'<tt>uint2fp .. to</tt>' Instruction</a></li>
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<li><a href="#i_sint2fp">'<tt>sint2fp .. to</tt>' Instruction</a></li>
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<li><a href="#i_fptoui">'<tt>fptoui .. to</tt>' Instruction</a></li>
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<li><a href="#i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a></li>
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<li><a href="#i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a></li>
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<li><a href="#i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a></li>
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<li><a href="#i_bitconvert">'<tt>bitconvert .. to</tt>' Instruction</a></li>
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</ol>
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<li><a href="#otherops">Other Operations</a>
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@ -1206,17 +1206,17 @@ following is the syntax for constant expressions:</p>
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constant. TYPE must be an integer type. CST must be floating point. If the
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value won't fit in the integer type, the results are undefined.</dd>
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<dt><b><tt>fp2sint ( CST to TYPE )</tt></b></dt>
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<dt><b><tt>fptosi ( CST to TYPE )</tt></b></dt>
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<dd>Convert a floating point constant to the corresponding signed integer
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constant. TYPE must be an integer type. CST must be floating point. If the
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value won't fit in the integer type, the results are undefined.</dd>
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<dt><b><tt>uint2fp ( CST to TYPE )</tt></b></dt>
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<dt><b><tt>uitofp ( CST to TYPE )</tt></b></dt>
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<dd>Convert an unsigned integer constant to the corresponding floating point
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constant. TYPE must be floating point. CST must be of integer type. If the
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value won't fit in the floating point type, the results are undefined.</dd>
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<dt><b><tt>sint2fp ( CST to TYPE )</tt></b></dt>
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<dt><b><tt>sitofp ( CST to TYPE )</tt></b></dt>
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<dd>Convert a signed integer constant to the corresponding floating point
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constant. TYPE must be floating point. CST must be of integer type. If the
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value won't fit in the floating point type, the results are undefined.</dd>
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@ -2640,19 +2640,15 @@ The '<tt>trunc</tt>' instruction truncates its operand to the type <tt>ty2</tt>.
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The '<tt>trunc</tt>' instruction takes a <tt>value</tt> to trunc, which must
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be an <a href="#t_integer">integer</a> type, and a type that specifies the size
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and type of the result, which must be an <a href="#t_integral">integral</a>
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type.</p>
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type. The bit size of <tt>value</tt> must be larger than the bit size of
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<tt>ty2</tt>. Equal sized types are not allowed.</p>
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<h5>Semantics:</h5>
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<p>
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The '<tt>trunc</tt>' instruction truncates the high order bits in <tt>value</tt>
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and converts the reamining bits to <tt>ty2</tt>. The bit size of <tt>value</tt>
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must be larger than the bit size of <tt>ty2</tt>. Equal sized types are not
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allowed. This implies that a <tt>trunc</tt> cannot be a <i>no-op cast</i>. It
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will always truncate bits.</p>
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<p>When truncating to bool, the truncation is done as a comparison against
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zero. If the <tt>value</tt> was zero, the bool result will be <tt>false</tt>.
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If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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and converts the remaining bits to <tt>ty2</tt>. Since the source size must be
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larger than the destination size, <tt>trunc</tt> cannot be a <i>no-op cast</i>.
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It will always truncate bits.</p>
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<h5>Example:</h5>
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<pre>
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@ -2681,8 +2677,8 @@ If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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<p>The '<tt>zext</tt>' instruction takes a value to cast, which must be of
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<a href="#t_integral">integral</a> type, and a type to cast it to, which must
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also be of <a href="#t_integral">integral</a> type. The bit size of the
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<tt>value</tt> must be smaller than or equal to the bit size of the
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destination type, <tt>ty2</tt>.</p>
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<tt>value</tt> must be smaller than the bit size of the destination type,
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<tt>ty2</tt>.</p>
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<h5>Semantics:</h5>
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<p>The <tt>zext</tt> fills the high order bits of the <tt>value</tt> with zero
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@ -2691,9 +2687,7 @@ the operand and the type are the same size, no bit filling is done and the
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cast is considered a <i>no-op cast</i> because no bits change (only the type
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changes).</p>
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<p>When zero extending to bool, the extension is done as a comparison against
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zero. If the <tt>value</tt> was zero, the bool result will be <tt>false</tt>.
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If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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<p>When zero extending from bool, the result will alwasy be either 0 or 1.</p>
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<h5>Example:</h5>
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<pre>
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@ -2720,7 +2714,9 @@ If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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<p>
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The '<tt>sext</tt>' instruction takes a value to cast, which must be of
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<a href="#t_integral">integral</a> type, and a type to cast it to, which must
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also be of <a href="#t_integral">integral</a> type.</p>
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also be of <a href="#t_integral">integral</a> type. The bit size of the
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<tt>value</tt> must be smaller than the bit size of the destination type,
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<tt>ty2</tt>.</p>
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<h5>Semantics:</h5>
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<p>
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@ -2730,12 +2726,9 @@ the type <tt>ty2</tt>. When the the operand and the type are the same size,
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no bit filling is done and the cast is considered a <i>no-op cast</i> because
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no bits change (only the type changes).</p>
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<p>When sign extending to bool, the extension is done as a comparison against
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zero. If the <tt>value</tt> was zero, the bool result will be <tt>false</tt>.
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If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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<p>When sign extending from bool, the extension always results in -1 or 0.</p>
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<h5>Example:</h5>
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<pre>
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%X = sext sbyte -1 to ushort <i>; yields ushort:65535</i>
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%Y = sext bool true to int <i>; yields int:-1</i>
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@ -2768,10 +2761,10 @@ cast it to. The size of <tt>value</tt> must be larger than the size of
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<i>no-op cast</i>.</p>
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<h5>Semantics:</h5>
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<p> The '<tt>fptrunc</tt>' instruction converts a
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<a href="#t_floating">floating point</a> value from a larger type to a smaller
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type. If the value cannot fit within the destination type, <tt>ty2</tt>, then
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the results are undefined.</p>
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<p> The '<tt>fptrunc</tt>' instruction truncates a <tt>value</tt> from a larger
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<a href="#t_floating">floating point</a> type to a smaller
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<a href="#t_floating">floating point</a> type. If the value cannot fit within
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the destination type, <tt>ty2</tt>, then the results are undefined.</p>
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<h5>Example:</h5>
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<pre>
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@ -2798,13 +2791,15 @@ floating point value.</p>
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<h5>Arguments:</h5>
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<p>The '<tt>fpext</tt>' instruction takes a
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<a href="#t_floating">floating point</a> <tt>value</tt> to cast,
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and a <a href="#t_floating">floating point</a> type to cast it to.</p>
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and a <a href="#t_floating">floating point</a> type to cast it to. The source
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type must be smaller than the destination type.</p>
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<h5>Semantics:</h5>
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<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from one floating
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point type to another. If the type of the <tt>value</tt> and <tt>ty2</tt> are
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the same, the instruction is considered a <i>no-op cast</i> because no bits
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change.</p>
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<p>The '<tt>fpext</tt>' instruction extends the <tt>value</tt> from a smaller
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<a href="t_floating">floating point</a> type to a larger
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<a href="t_floating">floating point</a> type. The <tt>fpext</tt> cannot be
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used to make a <i>no-op cast</i> because it always changes bits. Use
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<tt>bitconvert</tt> to make a <i>no-op cast</i> for a floating point cast.</p>
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<h5>Example:</h5>
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<pre>
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@ -2815,7 +2810,7 @@ change.</p>
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<!-- _______________________________________________________________________ -->
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<div class="doc_subsubsection">
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<a name="i_fp2uint">'<tt>fp2uint .. to</tt>' Instruction</a>
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<a name="i_fp2uint">'<tt>fptoui .. to</tt>' Instruction</a>
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</div>
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<div class="doc_text">
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@ -2854,28 +2849,28 @@ If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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<!-- _______________________________________________________________________ -->
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<div class="doc_subsubsection">
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<a name="i_fp2sint">'<tt>fp2sint .. to</tt>' Instruction</a>
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<a name="i_fptosi">'<tt>fptosi .. to</tt>' Instruction</a>
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</div>
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<div class="doc_text">
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<h5>Syntax:</h5>
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<pre>
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<result> = fp2sint <ty> <value> to <ty2> <i>; yields ty2</i>
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<result> = fptosi <ty> <value> to <ty2> <i>; yields ty2</i>
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</pre>
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<h5>Overview:</h5>
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<p>The '<tt>fp2sint</tt>' instruction converts
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<p>The '<tt>fptosi</tt>' instruction converts
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<a href="#t_floating">floating point</a> <tt>value</tt> to type <tt>ty2</tt>.
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</p>
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<h5>Arguments:</h5>
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<p> The '<tt>fp2sint</tt>' instruction takes a value to cast, which must be a
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<p> The '<tt>fptosi</tt>' instruction takes a value to cast, which must be a
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<a href="#t_floating">floating point</a> value, and a type to cast it to, which
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must also be an <a href="#t_integral">integral</a> type.</p>
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<h5>Semantics:</h5>
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<p>The '<tt>fp2sint</tt>' instruction converts its
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<p>The '<tt>fptosi</tt>' instruction converts its
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<a href="#t_floating">floating point</a> operand into the nearest (rounding
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towards zero) signed integer value. If the value cannot fit in <tt>ty2</tt>,
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the results are undefined.</p>
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@ -2886,75 +2881,75 @@ If the <tt>value</tt> was non-zero, the bool result will be <tt>true</tt>.</p>
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<h5>Example:</h5>
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<pre>
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%X = fp2sint double -123.0 to int <i>; yields int:-123</i>
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%Y = fp2sint float 1.0E-247 to bool <i>; yields bool:true</i>
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%X = fp2sint float 1.04E+17 to sbyte <i>; yields undefined:1</i>
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%X = fptosi double -123.0 to int <i>; yields int:-123</i>
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%Y = fptosi float 1.0E-247 to bool <i>; yields bool:true</i>
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%X = fptosi float 1.04E+17 to sbyte <i>; yields undefined:1</i>
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</pre>
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</div>
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<!-- _______________________________________________________________________ -->
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<div class="doc_subsubsection">
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<a name="i_uint2fp">'<tt>uint2fp .. to</tt>' Instruction</a>
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<a name="i_uitofp">'<tt>uitofp .. to</tt>' Instruction</a>
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</div>
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<div class="doc_text">
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<h5>Syntax:</h5>
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<pre>
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<result> = uint2fp <ty> <value> to <ty2> <i>; yields ty2</i>
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<result> = uitofp <ty> <value> to <ty2> <i>; yields ty2</i>
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</pre>
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<h5>Overview:</h5>
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<p>The '<tt>uint2fp</tt>' instruction regards <tt>value</tt> as an unsigned
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<p>The '<tt>uitofp</tt>' instruction regards <tt>value</tt> as an unsigned
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integer and converts that value to the <tt>ty2</tt> type.</p>
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<h5>Arguments:</h5>
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<p>The '<tt>uint2fp</tt>' instruction takes a value to cast, which must be an
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<p>The '<tt>uitofp</tt>' instruction takes a value to cast, which must be an
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<a href="#t_integral">integral</a> value, and a type to cast it to, which must
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be a <a href="#t_floating">floating point</a> type.</p>
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<h5>Semantics:</h5>
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<p>The '<tt>uint2fp</tt>' instruction interprets its operand as an unsigned
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<p>The '<tt>uitofp</tt>' instruction interprets its operand as an unsigned
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integer quantity and converts it to the corresponding floating point value. If
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the value cannot fit in the floating point value, the results are undefined.</p>
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<h5>Example:</h5>
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<pre>
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%X = uint2fp int 257 to float <i>; yields float:257.0</i>
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%Y = uint2fp sbyte -1 to double <i>; yields double:255.0</i>
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%X = uitofp int 257 to float <i>; yields float:257.0</i>
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%Y = uitofp sbyte -1 to double <i>; yields double:255.0</i>
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</pre>
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</div>
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<!-- _______________________________________________________________________ -->
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<div class="doc_subsubsection">
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<a name="i_sint2fp">'<tt>sint2fp .. to</tt>' Instruction</a>
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<a name="i_sitofp">'<tt>sitofp .. to</tt>' Instruction</a>
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</div>
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<div class="doc_text">
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<h5>Syntax:</h5>
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<pre>
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<result> = sint2fp <ty> <value> to <ty2> <i>; yields ty2</i>
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<result> = sitofp <ty> <value> to <ty2> <i>; yields ty2</i>
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</pre>
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<h5>Overview:</h5>
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<p>The '<tt>sint2fp</tt>' instruction regards <tt>value</tt> as a signed
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<p>The '<tt>sitofp</tt>' instruction regards <tt>value</tt> as a signed
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integer and converts that value to the <tt>ty2</tt> type.</p>
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<h5>Arguments:</h5>
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<p>The '<tt>sint2fp</tt>' instruction takes a value to cast, which must be an
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<p>The '<tt>sitofp</tt>' instruction takes a value to cast, which must be an
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<a href="#t_integral">integral</a> value, and a type to cast it to, which must be
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a <a href="#t_floating">floating point</a> type.</p>
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<h5>Semantics:</h5>
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<p>The '<tt>sint2fp</tt>' instruction interprets its operand as a signed
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<p>The '<tt>sitofp</tt>' instruction interprets its operand as a signed
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integer quantity and converts it to the corresponding floating point value. If
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the value cannot fit in the floating point value, the results are undefined.</p>
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<h5>Example:</h5>
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<pre>
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%X = sint2fp int 257 to float <i>; yields float:257.0</i>
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%Y = sint2fp sbyte -1 to double <i>; yields double:-1.0</i>
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%X = sitofp int 257 to float <i>; yields float:257.0</i>
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%Y = sitofp sbyte -1 to double <i>; yields double:-1.0</i>
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</pre>
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</div>
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@ -2983,8 +2978,8 @@ and the destination type, <tt>ty2</tt>, must be identical.</p>
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<p>The '<tt>bitconvert</tt>' instruction converts <tt>value</tt> to type
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<tt>ty2</tt> as if the value had been stored to memory and read back as type
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<tt>ty2</tt>. That is, no bits are changed during the conversion. The
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<tt>bitconvert</tt> instruction may be used to construct <i>no-op casts</i> that
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the <tt>zext, sext, and fpext</tt> instructions do not permit.</p>
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<tt>bitconvert</tt> instruction is the only conversion instruction that permits
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<i>no-op casts</i> to be constructed.</p>
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<h5>Example:</h5>
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<pre>
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