8 Commits

Author	SHA1	Message	Date
Paul Redmond	874f01e956	Do not vectorize loops with subtraction reductions ... Since subtraction does not commute the loop vectorizer incorrectly vectorizes reductions such as x = A[i] - x. Disabling for now. llvm-svn: 171537	2013-01-04 22:10:16 +00:00
Benjamin Kramer	f0e5d2f032	LoopVectorize: Emit reductions as log2(vectorsize) shuffles + vector ops instead of scalar operations. ... For example on x86 with SSE4.2 a <8 x i8> add reduction becomes movdqa %xmm0, %xmm1 movhlps %xmm1, %xmm1 ## xmm1 = xmm1[1,1] paddw %xmm0, %xmm1 pshufd $1, %xmm1, %xmm0 ## xmm0 = xmm1[1,0,0,0] paddw %xmm1, %xmm0 phaddw %xmm0, %xmm0 pextrb $0, %xmm0, %edx instead of pextrb $2, %xmm0, %esi pextrb $0, %xmm0, %edx addb %sil, %dl pextrb $4, %xmm0, %esi addb %dl, %sil pextrb $6, %xmm0, %edx addb %sil, %dl pextrb $8, %xmm0, %esi addb %dl, %sil pextrb $10, %xmm0, %edi pextrb $14, %xmm0, %edx addb %sil, %dil pextrb $12, %xmm0, %esi addb %dil, %sil addb %sil, %dl llvm-svn: 170439	2012-12-18 18:40:20 +00:00
Nadav Rotem	4cb8cdab5e	LoopVectorize: Preserve NSW, NUW and IsExact flags. ... llvm-svn: 167174	2012-10-31 21:40:39 +00:00
Nadav Rotem	b3e8e688da	LoopVectorize: Fix a bug in the initialization of reduction variables. AND needs to start at all-one ... while XOR, and OR need to start at zero. llvm-svn: 167032	2012-10-30 18:12:36 +00:00
Nadav Rotem	5ffb049a55	Add support for additional reduction variables: AND, OR, XOR. ... Patch by Paul Redmond <paul.redmond@intel.com>. llvm-svn: 166649	2012-10-25 00:08:41 +00:00
Nadav Rotem	a721b21c64	LoopVectorizer: Add a basic cost model which uses the VTTI interface. ... llvm-svn: 166620	2012-10-24 20:36:32 +00:00
Nadav Rotem	c1679a95b6	Add support for reduction variables that do not start at zero. ... This is important for nested-loop reductions such as : In the innermost loop, the induction variable does not start with zero: for (i = 0 .. n) for (j = 0 .. m) sum += ... llvm-svn: 166387	2012-10-21 05:52:51 +00:00
Nadav Rotem	4f7f72702b	Vectorizer: Add support for loop reductions. ... For example: for (i=0; i<n; i++) sum += A[i] + B[i] + i; llvm-svn: 166351	2012-10-19 23:05:40 +00:00