Nadav Rotem 8383b539ff Add support for bottom-up SLP vectorization infrastructure. ... This commit adds the infrastructure for performing bottom-up SLP vectorization (and other optimizations) on parallel computations. The infrastructure has three potential users: 1. The loop vectorizer needs to be able to vectorize AOS data structures such as (sum += A[i] + A[i+1]). 2. The BB-vectorizer needs this infrastructure for bottom-up SLP vectorization, because bottom-up vectorization is faster to compute. 3. A loop-roller needs to be able to analyze consecutive chains and roll them into a loop, in order to reduce code size. A loop roller does not need to create vector instructions, and this infrastructure separates the chain analysis from the vectorization. This patch also includes a simple (100 LOC) bottom up SLP vectorizer that uses the infrastructure, and can vectorize this code: void SAXPY(int *x, int *y, int a, int i) { x[i] = a * x[i] + y[i]; x[i+1] = a * x[i+1] + y[i+1]; x[i+2] = a * x[i+2] + y[i+2]; x[i+3] = a * x[i+3] + y[i+3]; } git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@179117 91177308-0d34-0410-b5e6-96231b3b80d8		2013-04-09 19:44:35 +00:00
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llvm	Add support for bottom-up SLP vectorization infrastructure.	2013-04-09 19:44:35 +00:00
llvm-c	Revert r178713	2013-04-04 17:40:53 +00:00