3 Commits

Author	SHA1	Message	Date
Nadav Rotem	d16c8d0d33	1. Remove the part of r153848 which optimizes shuffle-of-shuffle into a new ... shuffle node because it could introduce new shuffle nodes that were not supported efficiently by the target. 2. Add a more restrictive shuffle-of-shuffle optimization for cases where the second shuffle reverses the transformation of the first shuffle. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154266 91177308-0d34-0410-b5e6-96231b3b80d8	2012-04-07 21:19:08 +00:00
Nadav Rotem	4ac9081c71	This commit contains a few changes that had to go in together. ... 1. Simplify xor/and/or (bitcast(A), bitcast(B)) -> bitcast(op (A,B)) (and also scalar_to_vector). 2. Xor/and/or are indifferent to the swizzle operation (shuffle of one src). Simplify xor/and/or (shuff(A), shuff(B)) -> shuff(op (A, B)) 3. Optimize swizzles of shuffles: shuff(shuff(x, y), undef) -> shuff(x, y). 4. Fix an X86ISelLowering optimization which was very bitcast-sensitive. Code which was previously compiled to this: movd (%rsi), %xmm0 movdqa .LCPI0_0(%rip), %xmm2 pshufb %xmm2, %xmm0 movd (%rdi), %xmm1 pshufb %xmm2, %xmm1 pxor %xmm0, %xmm1 pshufb .LCPI0_1(%rip), %xmm1 movd %xmm1, (%rdi) ret Now compiles to this: movl (%rsi), %eax xorl %eax, (%rdi) ret git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153848 91177308-0d34-0410-b5e6-96231b3b80d8	2012-04-01 19:31:22 +00:00
Nadav Rotem	b00418af67	Add a new DAGCombine optimization for BUILD_VECTOR. ... If all of the inputs are zero/any_extended, create a new simple BV which can be further optimized by other BV optimizations. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@143297 91177308-0d34-0410-b5e6-96231b3b80d8	2011-10-29 21:23:04 +00:00