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| -rw-r--r-- | docs/ReleaseNotes.html | 49 |
1 files changed, 37 insertions, 12 deletions
diff --git a/docs/ReleaseNotes.html b/docs/ReleaseNotes.html index fa926eb984..405cffa3e3 100644 --- a/docs/ReleaseNotes.html +++ b/docs/ReleaseNotes.html @@ -193,12 +193,13 @@ front-ends and driver with the LLVM optimizer and code generator. It currently includes support for the C, C++, Objective-C, Ada, and Fortran front-ends.</p> <ul> -<li>LLVM 2.4 supports the full set of atomic __sync builtins. LLVM 2.3 only -supported those used by OpenMP, but 2.4 supports them all. Not all targets -support all builtins, but X86 and PowerPC do.</li> +<li>LLVM 2.4 supports the full set of atomic <tt>__sync_*</tt> builtins. LLVM +2.3 only supported those used by OpenMP, but 2.4 supports them all. While +llvm-gcc supports all of these builtins, note that not all targets do. X86 and +PowerPC are known to support them all in both 32-bit and 64-bit mode.</li> -<li>llvm-gcc now supports an -flimited-precision option, which tells the -compiler that it is ok to use low-precision approximations of certain libm +<li>llvm-gcc now supports an <tt>-flimited-precision</tt> option, which tells +the compiler that it is ok to use low-precision approximations of certain libm functions (like tan, log, etc). This allows you to get high performance if you only need (say) 14-bits of precision.</li> @@ -229,15 +230,39 @@ Previously, LTO could only be used with -O4, which implied optimizations in </p> <ul> -<li>vector shifts in the IR: no codegen support yet</li> -<li>use diet patch landed: saved 15% IR memory footprint</li> +<li>A major change to the "Use" class landed, which shrank it by 25%. Since +this is a pervasive part of the LLVM, it ended up reducing the memory use of +LLVM IR in general by 15% for most programs.</li> + +<li>Values with no names are now pretty printed by <tt>llvm-dis</tt> more +nicely. They now print as "<tt>%3 = add i32 %A, 4</tt>" instead of +"<tt>add i32 %A, 4 ; <i32>:3</tt>", which makes it much easier to read. +</li> + +<li>LLVM 2.4 includes some changes for better vector support. First, the shift +operations (<tt>shl</tt>, <tt>ashr</tt>, <tt>lshr</tt>) now all support vectors +and do an element-by-element shift (shifts of the whole vector can be +accomplished by bitcasting the vector to <1 x i128> for example). Second, +there is support in development for vector comparisons. LLVM 2.4 actually +supports two ways to do vector comparisons: the vicmp/vfcmp instructions and the +icmp/fcmp instructions. The vicmp/vfcmp instructions are temporary and will be +removed (do not use them). The icmp/fcmp instructions compare two vectors and +return a vector of i1's for each result. Note that there is very little codegen +support available for any of these IR features though.</li> + +<li>A new <tt>DebugInfoBuilder</tt> class is available, which makes it much +easier for front-ends to create debug info descriptors, similar to the way that +IRBuilder makes it easier to create LLVM IR.</li> + +<li>LLVM now supports "function attributes", which allows us to seperate return +value attributes from function attributes. LLVM now supports attributes on a +function itself, a return value, and its parameters. New supported function +attributes include noinline/alwaysinline and the "opt-size" flag which says the +function should be optimized for code size.</li> + <li>LLVM IR now directly represents "common" linkage, instead of representing it as a form of weak linkage.</li> -<li>DebugInfoBuilder</li> -<li>.ll printing format change: %3 = add i32 4, 2</li> -<li>opt-size, noinline, alwaysinline function attributes</li> -<li>Attrs: function, return, param.</p></li> -<li>...</li> + </ul> </div> |