[llvm-commits] [llvm] r168652 - /llvm/trunk/docs/LangRef.html

[Sean Silva]

It seems needlessly repetitious end non-future-proof to copypaste the
description of the flags for each instruction. Why don't you split
them out into a section similar to how "Atomic Memory Ordering
Constraints" <http://llvm.org/docs/LangRef.html#ordering> has been
split out?

-- Sean Silva

On Mon, Nov 26, 2012 at 7:48 PM, Michael Ilseman <milseman at apple.com> wrote:
> Author: milseman
> Date: Mon Nov 26 18:48:29 2012
> New Revision: 168652
>
> URL: http://llvm.org/viewvc/llvm-project?rev=168652&view=rev
> Log:
> Fast-math flags documentation added to LangRef
>
>
> Modified:
>     llvm/trunk/docs/LangRef.html
>
> Modified: llvm/trunk/docs/LangRef.html
> URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/LangRef.html?rev=168652&r1=168651&r2=168652&view=diff
> ==============================================================================
> --- llvm/trunk/docs/LangRef.html (original)
> +++ llvm/trunk/docs/LangRef.html Mon Nov 26 18:48:29 2012
> @@ -3970,7 +3970,7 @@
>
>  <h5>Syntax:</h5>
>  <pre>
> -  <result> = fadd <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
> +  <result> = fadd [fast-math flags]* <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
>  </pre>
>
>  <h5>Overview:</h5>
> @@ -3982,7 +3982,28 @@
>     floating point values. Both arguments must have identical types.</p>
>
>  <h5>Semantics:</h5>
> -<p>The value produced is the floating point sum of the two operands.</p>
> +<p>The value produced is the floating point sum of the two operands. This
> +  instruction can also take any number of fast-math flags, which are
> +  optimization hints to enable otherwise unsafe floating point
> +  optimizations:</p>
> +<ol>
> +
> +  <li><tt>nnan</tt>: No NaNs - Allow optimizations to assume the arguments and
> +  result are not NaN. Such optimizations are required to retain defined behavior
> +  over NaNs, but the value of the result is undefined.</li>
> +
> +  <li><tt>ninf</tt>: No Inf - Allow optimizations to assume the arguments and
> +  result are not +/-Inf. Such optimizations are required to retain defined
> +  behavior over +/-Inf, but the value of the result is undefined.</li>
> +
> +  <li><tt>nsz</tt>: No Signed Zeros: Allow optimizations to treat the
> +  sign of a zero argument or result as insignificant. </li>
> +
> +  <li><tt>fast</tt>: Allow algebraically equivalent transformations that may
> +  dramatically change results in floating point (e.g. reassociate). This flag
> +  implies all the others.</li>
> +
> +</ol>
>
>  <h5>Example:</h5>
>  <pre>
> @@ -4052,7 +4073,7 @@
>
>  <h5>Syntax:</h5>
>  <pre>
> -  <result> = fsub <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
> +  <result> = fsub [fast-math flags]* <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
>  </pre>
>
>  <h5>Overview:</h5>
> @@ -4069,7 +4090,28 @@
>     floating point values.  Both arguments must have identical types.</p>
>
>  <h5>Semantics:</h5>
> -<p>The value produced is the floating point difference of the two operands.</p>
> +<p>The value produced is the floating point difference of the two operands.  This
> +  instruction can also take any number of fast-math flags, which are
> +  optimization hints to enable otherwise unsafe floating point
> +  optimizations:</p>
> +<ol>
> +
> +  <li><tt>nnan</tt>: No NaNs - Allow optimizations to assume the arguments and
> +  result are not NaN. Such optimizations are required to retain defined behavior
> +  over NaNs, but the value of the result is undefined.</li>
> +
> +  <li><tt>ninf</tt>: No Inf - Allow optimizations to assume the arguments and
> +  result are not +/-Inf. Such optimizations are required to retain defined
> +  behavior over +/-Inf, but the value of the result is undefined.</li>
> +
> +  <li><tt>nsz</tt>: No Signed Zeros: Allow optimizations to treat the
> +  sign of a zero argument or result as insignificant. </li>
> +
> +  <li><tt>fast</tt>: Allow algebraically equivalent transformations that may
> +  dramatically change results in floating point (e.g. reassociate). This flag
> +  implies all the others.</li>
> +
> +</ol>
>
>  <h5>Example:</h5>
>  <pre>
> @@ -4138,7 +4180,7 @@
>
>  <h5>Syntax:</h5>
>  <pre>
> -  <result> = fmul <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
> +  <result> = fmul [fast-math flags]* <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
>  </pre>
>
>  <h5>Overview:</h5>
> @@ -4150,7 +4192,28 @@
>     floating point values.  Both arguments must have identical types.</p>
>
>  <h5>Semantics:</h5>
> -<p>The value produced is the floating point product of the two operands.</p>
> +<p>The value produced is the floating point product of the two operands.  This
> +  instruction can also take any number of fast-math flags, which are
> +  optimization hints to enable otherwise unsafe floating point
> +  optimizations:</p>
> +<ol>
> +
> +  <li><tt>nnan</tt>: No NaNs - Allow optimizations to assume the arguments and
> +  result are not NaN. Such optimizations are required to retain defined behavior
> +  over NaNs, but the value of the result is undefined.</li>
> +
> +  <li><tt>ninf</tt>: No Inf - Allow optimizations to assume the arguments and
> +  result are not +/-Inf. Such optimizations are required to retain defined
> +  behavior over +/-Inf, but the value of the result is undefined.</li>
> +
> +  <li><tt>nsz</tt>: No Signed Zeros: Allow optimizations to treat the
> +  sign of a zero argument or result as insignificant. </li>
> +
> +  <li><tt>fast</tt>: Allow algebraically equivalent transformations that may
> +  dramatically change results in floating point (e.g. reassociate). This flag
> +  implies all the others.</li>
> +
> +</ol>
>
>  <h5>Example:</h5>
>  <pre>
> @@ -4252,7 +4315,7 @@
>
>  <h5>Syntax:</h5>
>  <pre>
> -  <result> = fdiv <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
> +  <result> = fdiv [fast-math flags]* <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
>  </pre>
>
>  <h5>Overview:</h5>
> @@ -4264,7 +4327,32 @@
>     floating point values.  Both arguments must have identical types.</p>
>
>  <h5>Semantics:</h5>
> -<p>The value produced is the floating point quotient of the two operands.</p>
> +<p>The value produced is the floating point quotient of the two operands. This
> +  instruction can also take any number of fast-math flags, which are
> +  optimization hints to enable otherwise unsafe floating point
> +  optimizations:</p>
> +<ol>
> +
> +  <li><tt>nnan</tt>: No NaNs - Allow optimizations to assume the arguments and
> +  result are not NaN. Such optimizations are required to retain defined behavior
> +  over NaNs, but the value of the result is undefined.</li>
> +
> +  <li><tt>ninf</tt>: No Inf - Allow optimizations to assume the arguments and
> +  result are not +/-Inf. Such optimizations are required to retain defined
> +  behavior over +/-Inf, but the value of the result is undefined.</li>
> +
> +  <li><tt>nsz</tt>: No Signed Zeros: Allow optimizations to treat the
> +  sign of a zero argument or result as insignificant. </li>
> +
> +  <li><tt>arcp</tt>: Allow Reciprocal: Allow optimizations to use the reciprocal
> +  of an argument rather than perform division. </li>
> +
> +  <li><tt>fast</tt>: Allow algebraically equivalent transformations that may
> +  dramatically change results in floating point (e.g. reassociate). This flag
> +  implies all the others.</li>
> +
> +</ol>
> +</p>
>
>  <h5>Example:</h5>
>  <pre>
> @@ -4371,7 +4459,7 @@
>
>  <h5>Syntax:</h5>
>  <pre>
> -  <result> = frem <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
> +  <result> = frem [fast-math flags]* <ty> <op1>, <op2>   <i>; yields {ty}:result</i>
>  </pre>
>
>  <h5>Overview:</h5>
> @@ -4384,8 +4472,32 @@
>     floating point values.  Both arguments must have identical types.</p>
>
>  <h5>Semantics:</h5>
> -<p>This instruction returns the <i>remainder</i> of a division.  The remainder
> -   has the same sign as the dividend.</p>
> +  <p>This instruction returns the <i>remainder</i> of a division.  The remainder
> +   has the same sign as the dividend.  This instruction can also take any number
> +   of fast-math flags, which are optimization hints to enable otherwise unsafe
> +   floating point optimizations:</p>
> +
> +<ol>
> +
> +  <li><tt>nnan</tt>: No NaNs - Allow optimizations to assume the arguments and
> +  result are not NaN. Such optimizations are required to retain defined behavior
> +  over NaNs, but the value of the result is undefined.</li>
> +
> +  <li><tt>ninf</tt>: No Inf - Allow optimizations to assume the arguments and
> +  result are not +/-Inf. Such optimizations are required to retain defined
> +  behavior over +/-Inf, but the value of the result is undefined.</li>
> +
> +  <li><tt>nsz</tt>: No Signed Zeros: Allow optimizations to treat the
> +  sign of a zero argument or result as insignificant. </li>
> +
> +  <li><tt>arcp</tt>: Allow Reciprocal: Allow optimizations to use the reciprocal
> +  of an argument rather than perform division. </li>
> +
> +  <li><tt>fast</tt>: Allow algebraically equivalent transformations that may
> +  dramatically change results in floating point (e.g. reassociate). This flag
> +  implies all the others.</li>
> +
> +</ol>
>
>  <h5>Example:</h5>
>  <pre>
>
>
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