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
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Analysis	implement two helper methods	2005-08-09 23:36:33 +00:00
AsmParser	Fix grammar	2005-06-24 18:00:40 +00:00
Bytecode	Eliminate all remaining tabs and trailing spaces.	2005-07-27 06:12:32 +00:00
CodeGen	Fix spelling, fix some broken canonicalizations by my last patch	2005-08-09 23:09:05 +00:00
Debugger	For PR495:	2005-07-07 23:21:43 +00:00
ExecutionEngine	one cannot allocate a global, until one is done initializing the global pointers	2005-08-01 17:35:40 +00:00
Linker	For PR495:	2005-07-07 23:21:43 +00:00
Support	Allow tools with "consume after" options (like lli) to take more positional	2005-08-08 21:57:27 +00:00
System	Fix grammar: it's == "it is".	2005-08-02 16:04:59 +00:00
Target	add a optimization note	2005-08-09 22:30:57 +00:00
Transforms	Teach LSR to strength reduce IVs that have a loop-invariant but non-constant stride.	2005-08-10 00:45:21 +00:00
VMCore	add new helper function	2005-08-08 05:21:50 +00:00
Makefile	Add the Linker library	2004-11-14 21:54:41 +00:00