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| author | Nuno Lopes <nunoplopes@sapo.pt> | 2012-05-09 15:52:43 +0000 |
|---|---|---|
| committer | Nuno Lopes <nunoplopes@sapo.pt> | 2012-05-09 15:52:43 +0000 |
| commit | 30759542aa820b9fc74c77bfa3c011cb0a106ef9 (patch) | |
| tree | 9698461a0cd7c16beea9446415a512f3e3bcde0e /docs/LangRef.html | |
| parent | 80fa4723b9b7cb9d78d71648095e4e2804681402 (diff) | |
| download | external_llvm-30759542aa820b9fc74c77bfa3c011cb0a106ef9.zip external_llvm-30759542aa820b9fc74c77bfa3c011cb0a106ef9.tar.gz external_llvm-30759542aa820b9fc74c77bfa3c011cb0a106ef9.tar.bz2 | |
change the objectsize intrinsic signature: add a 3rd parameter to denote the maximum runtime performance penalty that the user is willing to accept.
This commit only adds the parameter. Code taking advantage of it will follow.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156473 91177308-0d34-0410-b5e6-96231b3b80d8
Diffstat (limited to 'docs/LangRef.html')
| -rw-r--r-- | docs/LangRef.html | 24 |
1 files changed, 14 insertions, 10 deletions
diff --git a/docs/LangRef.html b/docs/LangRef.html index cdf2807..b222b06 100644 --- a/docs/LangRef.html +++ b/docs/LangRef.html @@ -8441,8 +8441,8 @@ LLVM</a>.</p> <h5>Syntax:</h5> <pre> - declare i32 @llvm.objectsize.i32(i8* <object>, i1 <type>) - declare i64 @llvm.objectsize.i64(i8* <object>, i1 <type>) + declare i32 @llvm.objectsize.i32(i8* <object>, i1 <min>, i32 <runtime>) + declare i64 @llvm.objectsize.i64(i8* <object>, i1 <min>, i32 <runtime>) </pre> <h5>Overview:</h5> @@ -8453,17 +8453,21 @@ LLVM</a>.</p> an allocation of a specific class, structure, array, or other object.</p> <h5>Arguments:</h5> -<p>The <tt>llvm.objectsize</tt> intrinsic takes two arguments. The first +<p>The <tt>llvm.objectsize</tt> intrinsic takes three arguments. The first argument is a pointer to or into the <tt>object</tt>. The second argument - is a boolean 0 or 1. This argument determines whether you want the - maximum (0) or minimum (1) bytes remaining. This needs to be a literal 0 or - 1, variables are not allowed.</p> + is a boolean and determines whether <tt>llvm.objectsize</tt> returns 0 (if true) + or -1 (if false) when the object size is unknown. + The third argument, <tt>runtime</tt>, indicates whether the compiler is allowed + to return a non-constant value. The higher the value, the higher the potential + run-time performance impact. + The second and third arguments only accepts constants.</p> <h5>Semantics:</h5> -<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to either a constant - representing the size of the object concerned, or <tt>i32/i64 -1 or 0</tt>, - depending on the <tt>type</tt> argument, if the size cannot be determined at - compile time.</p> +<p>The <tt>llvm.objectsize</tt> intrinsic is lowered to a constant representing + the size of the object concerned. If the size cannot be determined at compile + time, <tt>llvm.objectsize</tt> either returns <tt>i32/i64 -1 or 0</tt> + (depending on the <tt>min</tt> argument) if <tt>runtime</tt> is 0, or a run-time + value (if <tt>runtime</tt> > 0 and an expression could be generated).</p> </div> <!-- _______________________________________________________________________ --> |