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

[Michael Ilseman]

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>