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| -rw-r--r-- | docs/LangRef.html | 37 |
1 files changed, 26 insertions, 11 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html index dced11c441..334cb68772 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -2600,7 +2600,9 @@ Instruction</a> </div> <h5>Syntax:</h5> <pre> - <result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = add <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = signed add <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = unsigned add <ty> <op1>, <op2> <i>; yields {ty}:result</i> </pre> <h5>Overview:</h5> @@ -2620,6 +2622,10 @@ Instruction</a> </div> <p>Because LLVM integers use a two's complement representation, this instruction is appropriate for both signed and unsigned integers.</p> +<p>If the <tt>signed</tt> and/or <tt>unsigned</tt> keywords are present, + the behavior of the <tt>add</tt> is undefined if signed and/or unsigned + overflow, respectively, occurs.</p> + <h5>Example:</h5> <pre> <result> = add i32 4, %var <i>; yields {i32}:result = 4 + %var</i> @@ -2666,7 +2672,9 @@ Instruction</a> </div> <h5>Syntax:</h5> <pre> - <result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = sub <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = signed sub <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = unsigned sub <ty> <op1>, <op2> <i>; yields {ty}:result</i> </pre> <h5>Overview:</h5> @@ -2692,6 +2700,10 @@ Instruction</a> </div> <p>Because LLVM integers use a two's complement representation, this instruction is appropriate for both signed and unsigned integers.</p> +<p>If the <tt>signed</tt> and/or <tt>unsigned</tt> keywords are present, + the behavior of the <tt>sub</tt> is undefined if signed and/or unsigned + overflow, respectively, occurs.</p> + <h5>Example:</h5> <pre> <result> = sub i32 4, %var <i>; yields {i32}:result = 4 - %var</i> @@ -2745,7 +2757,9 @@ Instruction</a> </div> <h5>Syntax:</h5> <pre> - <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = mul <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = signed mul <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = unsigned mul <ty> <op1>, <op2> <i>; yields {ty}:result</i> </pre> <h5>Overview:</h5> @@ -2770,6 +2784,10 @@ Instruction</a> </div> be sign-extended or zero-extended as appropriate to the width of the full product.</p> +<p>If the <tt>signed</tt> and/or <tt>unsigned</tt> keywords are present, + the behavior of the <tt>mul</tt> is undefined if signed and/or unsigned + overflow, respectively, occurs.</p> + <h5>Example:</h5> <pre> <result> = mul i32 4, %var <i>; yields {i32}:result = 4 * %var</i> @@ -2849,7 +2867,8 @@ Instruction</a> </div> <h5>Syntax:</h5> <pre> - <result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i> + <result> = exact sdiv <ty> <op1>, <op2> <i>; yields {ty}:result</i> </pre> <h5>Overview:</h5> @@ -2871,6 +2890,9 @@ Instruction</a> </div> undefined behavior; this is a rare case, but can occur, for example, by doing a 32-bit division of -2147483648 by -1.</p> +<p>If the <tt>exact</tt> keyword is present, the result of the <tt>sdiv</tt> + is undefined if the result would be rounded or if overflow occurs.</p> + <h5>Example:</h5> <pre> <result> = sdiv i32 4, %var <i>; yields {i32}:result = 4 / %var</i> @@ -3912,13 +3934,6 @@ entry: } </pre> -<p>Note that it is undefined to access an array out of bounds: array and pointer - indexes must always be within the defined bounds of the array type when - accessed with an instruction that dereferences the pointer (e.g. a load or - store instruction). The one exception for this rule is zero length arrays. - These arrays are defined to be accessible as variable length arrays, which - requires access beyond the zero'th element.</p> - <p>The getelementptr instruction is often confusing. For some more insight into how it works, see <a href="GetElementPtr.html">the getelementptr FAQ</a>.</p> |