From: Chris Lattner Date: Fri, 12 Mar 2004 05:50:16 +0000 (+0000) Subject: Cleanup the cast section, add the select instruction X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=cc37aae854d1778b2d446a5d3bf7d43dfae088a1;p=oota-llvm.git Cleanup the cast section, add the select instruction git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@12307 91177308-0d34-0410-b5e6-96231b3b80d8 --- diff --git a/docs/LangRef.html b/docs/LangRef.html index 3215586f864..de0ac2efdf4 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -80,6 +80,7 @@
  1. 'phi' Instruction
  2. 'cast .. to' Instruction
    3. +
  3. 'select' Instruction
  4. 'call' Instruction
  5. 'vanext' Instruction
  6. 'vaarg' Instruction
    7. @@ -1506,38 +1507,111 @@ came from in the last terminator instruction.

    Example:
    Loop:       ; Infinite loop that counts from 0 on up...
      %indvar = phi uint [ 0, %LoopHeader ], [ %nextindvar, %Loop ]
      %nextindvar = add uint %indvar, 1
      br label %Loop
    + -
    'cast .. to' -Instruction
    +
    + 'cast .. to' Instruction +
    +
    +
    Syntax:
    -
      <result> = cast <ty> <value> to <ty2>             ; yields ty2
+
+
    +  <result> = cast <ty> <value> to <ty2>             ; yields ty2
 
    
+
 
    Overview:
    
-
    The 'cast' instruction is used as the primitive means to
-convert integers to floating point, change data type sizes, and break
-type safety (by casting pointers).
    
+
+
    
+The 'cast' instruction is used as the primitive means to convert
+integers to floating point, change data type sizes, and break type safety (by
+casting pointers).
+
    
+
+
 
    Arguments:
    
-
    The 'cast' instruction takes a value to cast, which must be
-a first class value, and a type to cast it to, which must also be a first class type.
    
+
+
    
+The 'cast' instruction takes a value to cast, which must be a first
+class value, and a type to cast it to, which must also be a first class type.
+
    
+
 
    Semantics:
    
-
    This instruction follows the C rules for explicit casts when
-determining how the data being cast must change to fit in its new
-container.
    
-
    When casting to bool, any value that would be considered true in the
-context of a C 'if' condition is converted to the boolean 'true'
-values, all else are 'false'.
    
-
    When extending an integral value from a type of one signness to
-another (for example 'sbyte' to 'ulong'), the value
-is sign-extended if the source value is signed, and
-zero-extended if the source value is unsigned. bool values
-are always zero extended into either zero or one.
    
+
+
    
+This instruction follows the C rules for explicit casts when determining how the
+data being cast must change to fit in its new container.
+
    
+
+
    
+When casting to bool, any value that would be considered true in the context of
+a C 'if' condition is converted to the boolean 'true' values,
+all else are 'false'.
+
    
+
+
    
+When extending an integral value from a type of one signness to another (for
+example 'sbyte' to 'ulong'), the value is sign-extended if the
+source value is signed, and zero-extended if the source value is
+unsigned. bool values are always zero extended into either zero or
+one.
+
    
+
 
    Example:
    
-
      %X = cast int 257 to ubyte              ; yields ubyte:1
+
+
    +  %X = cast int 257 to ubyte              ; yields ubyte:1
   %Y = cast int 123 to bool               ; yields bool:true
    + + +
    + 'select' Instruction +
    + +
    + +
    Syntax:
    + +
    +  <result> = select bool <cond>, <ty> <val1>, <ty> <val2>             ; yields ty
+
    + +
    Overview:
    + +

    +The 'select' instruction is used to choose one value based on a +condition, without branching. +

    + + +
    Arguments:
    + +

    +The 'select' instruction requires a boolean value indicating the condition, and two values of the same first class type. +

    + +
    Semantics:
    + +

    +If the boolean condition evaluates to true, the instruction returns the first +value argument, otherwise it returns the second value argument. +

    + +
    Example:
    + +
    +  %X = select bool true, ubyte 17, ubyte 42          ; yields ubyte:17
+
    +
    + + + + +
    'call' Instruction