Chris Lattner 8c7e769325 Teach LSR to strength reduce IVs that have a loop-invariant but non-constant stride. ... For code like this: void foo(float *a, float *b, int n, int stride_a, int stride_b) { int i; for (i=0; i<n; i++) a[i*stride_a] = b[i*stride_b]; } we now emit: .LBB_foo2_2: ; no_exit lfs f0, 0(r4) stfs f0, 0(r3) addi r7, r7, 1 add r4, r2, r4 add r3, r6, r3 cmpw cr0, r7, r5 blt .LBB_foo2_2 ; no_exit instead of: .LBB_foo_2: ; no_exit mullw r8, r2, r7 ;; multiply! slwi r8, r8, 2 lfsx f0, r4, r8 mullw r8, r2, r6 ;; multiply! slwi r8, r8, 2 stfsx f0, r3, r8 addi r2, r2, 1 cmpw cr0, r2, r5 blt .LBB_foo_2 ; no_exit loops with variable strides occur pretty often. For example, in SPECFP2K there are 317 variable strides in 177.mesa, 3 in 179.art, 14 in 188.ammp, 56 in 168.wupwise, 36 in 172.mgrid. Now we can allow indvars to turn functions written like this: void foo2(float *a, float *b, int n, int stride_a, int stride_b) { int i, ai = 0, bi = 0; for (i=0; i<n; i++) { a[ai] = b[bi]; ai += stride_a; bi += stride_b; } } into code like the above for better analysis. With this patch, they generate identical code. llvm-svn: 22740		2005-08-10 00:45:21 +00:00
..
ADCE.cpp	preserve calling conventions when hacking on code	2005-05-14 12:25:32 +00:00
BasicBlockPlacement.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
CondPropagate.cpp	Fix a fixme in CondPropagate.cpp by moving a PhiNode optimization into	2005-08-04 23:24:19 +00:00
ConstantProp.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
CorrelatedExprs.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
DCE.cpp	clean up and modernize this pass.	2005-05-08 18:45:26 +00:00
DeadStoreElimination.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
GCSE.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
IndVarSimplify.cpp	Break SCEVExpander out of IndVarSimplify into its own .h/.cpp file so that	2005-07-30 00:12:19 +00:00
InstructionCombining.cpp	Use the new 'moveBefore' method to simplify some code. Really, which is	2005-08-08 19:11:57 +00:00
LICM.cpp	prevent va_arg from being hoisted from a loop	2005-06-20 13:36:33 +00:00
LoopSimplify.cpp	This code can handle non-dominating instructions	2005-08-05 00:57:45 +00:00
LoopStrengthReduce.cpp	Teach LSR to strength reduce IVs that have a loop-invariant but non-constant stride.	2005-08-10 00:45:21 +00:00
LoopUnroll.cpp	Eliminate tabs and trailing spaces	2005-04-23 21:38:35 +00:00
LoopUnswitch.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
LowerAllocations.cpp	Preserve tail marker	2005-05-06 06:48:21 +00:00
LowerConstantExprs.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
LowerGC.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
LowerInvoke.cpp	The correct fix for PR612, which also fixes	2005-08-03 18:51:44 +00:00
LowerPacked.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
LowerSelect.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
LowerSwitch.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
Makefile	Change Library Names Not To Conflict With Others When Installed	2004-10-27 23:18:45 +00:00
Mem2Reg.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
PRE.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
Reassociate.cpp	Use the new 'moveBefore' method to simplify some code. Really, which is	2005-08-08 19:11:57 +00:00
ScalarReplAggregates.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
SCCP.cpp	Eliminate tabs and trailing spaces	2005-04-23 21:38:35 +00:00
SimplifyCFG.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
TailDuplication.cpp	Remove trailing whitespace	2005-04-21 23:48:37 +00:00
TailRecursionElimination.cpp	Use the new 'moveBefore' method to simplify some code. Really, which is	2005-08-08 19:11:57 +00:00