forked from OSchip/llvm-project
dc8a41de34
The patch attempts to optimize a sequence of SIMD loads from the same
base pointer:
%0 = gep float*, float* base, i32 4
%1 = bitcast float* %0 to <4 x float>*
%2 = load <4 x float>, <4 x float>* %1
...
%n1 = gep float*, float* base, i32 N
%n2 = bitcast float* %n1 to <4 x float>*
%n3 = load <4 x float>, <4 x float>* %n2
For AArch64 the compiler generates a sequence of LDR Qt, [Xn, #16].
However, 32-bit NEON VLD1/VST1 lack the [Wn, #imm] addressing mode, so
the address is computed before every ld/st instruction:
add r2, r0, #32
add r0, r0, #16
vld1.32 {d18, d19}, [r2]
vld1.32 {d22, d23}, [r0]
This can be improved by computing address for the first load, and then
using a post-indexed form of VLD1/VST1 to load the rest:
add r0, r0, #16
vld1.32 {d18, d19}, [r0]!
vld1.32 {d22, d23}, [r0]
In order to do that, the patch adds more patterns to DAGCombine:
- (load (add ptr inc1)) and (add ptr inc2) are now folded if inc1
and inc2 are constants.
- (or ptr inc) is now recognized as a pointer increment if ptr is
sufficiently aligned.
In addition to that, we now search for all possible base updates and
then pick the best one.
Differential Revision: https://reviews.llvm.org/D108988
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|---|---|---|
| .. | ||
| AArch64 | ||
| AMDGPU | ||
| ARM | ||
| NVPTX | ||
| Power | ||
| X86 | ||
| 2005-08-15-AddRecIV.ll | ||
| 2005-08-17-OutOfLoopVariant.ll | ||
| 2005-09-12-UsesOutOutsideOfLoop.ll | ||
| 2007-04-23-UseIterator.ll | ||
| 2008-08-13-CmpStride.ll | ||
| 2008-09-09-Overflow.ll | ||
| 2009-01-13-nonconstant-stride-outside-loop.ll | ||
| 2009-04-28-no-reduce-mul.ll | ||
| 2011-07-19-CritEdgeBreakCrash.ll | ||
| 2011-10-03-CritEdgeMerge.ll | ||
| 2011-10-06-ReusePhi.ll | ||
| 2011-10-13-SCEVChain.ll | ||
| 2011-10-14-IntPtr.ll | ||
| 2011-12-19-PostincQuadratic.ll | ||
| 2012-01-02-nopreheader.ll | ||
| 2012-01-16-nopreheader.ll | ||
| 2012-03-15-nopreheader.ll | ||
| 2012-03-26-constexpr.ll | ||
| 2012-07-13-ExpandUDiv.ll | ||
| 2012-07-18-LimitReassociate.ll | ||
| 2013-01-05-IndBr.ll | ||
| 2013-01-14-ReuseCast.ll | ||
| addrec-gep-address-space.ll | ||
| addrec-gep.ll | ||
| address-space-loop.ll | ||
| callbr-critical-edge-splitting.ll | ||
| callbr-critical-edge-splitting2.ll | ||
| count-to-zero.ll | ||
| dbg-preserve-0.ll | ||
| dbg-preserve-1.ll | ||
| dbg-preserve-2.ll | ||
| dead-phi.ll | ||
| debuginfo-scev-salvage-0.ll | ||
| debuginfo-scev-salvage-1.ll | ||
| debuginfo-scev-salvage-2.ll | ||
| debuginfo-scev-salvage-3.ll | ||
| debuginfo-scev-salvage-4.ll | ||
| different-type-ivs.ll | ||
| dominate-assert.ll | ||
| dont-hoist-simple-loop-constants.ll | ||
| dont_insert_redundant_ops.ll | ||
| dont_reduce_bytes.ll | ||
| dont_reverse.ll | ||
| ephemeral.ll | ||
| exit_compare_live_range.ll | ||
| funclet.ll | ||
| gnarly-setupcost.ll | ||
| hoist-parent-preheader.ll | ||
| illegal-addr-modes.ll | ||
| invariant_value_first.ll | ||
| invariant_value_first_arg.ll | ||
| ivchain.ll | ||
| lsr-comp-time.ll | ||
| lsr-overflow.ll | ||
| missing-phi-operand-update.ll | ||
| multi-edge-latch.ll | ||
| negative-scale.ll | ||
| nested-reduce.ll | ||
| nonintegral.ll | ||
| nonlinear-postinc.ll | ||
| opaque-ptr.ll | ||
| ops_after_indvar.ll | ||
| optimizemax_debugloc.ll | ||
| phi_node_update_multiple_preds.ll | ||
| post-inc-icmpzero.ll | ||
| post-inc-optsize.ll | ||
| post-increment-insertion.ll | ||
| pr2537.ll | ||
| pr2570.ll | ||
| pr3086.ll | ||
| pr3399.ll | ||
| pr3571.ll | ||
| pr12018.ll | ||
| pr12048.ll | ||
| pr12691.ll | ||
| pr18165.ll | ||
| pr25541.ll | ||
| pr27056.ll | ||
| pr31627.ll | ||
| pr48725.ll | ||
| pr50765.ll | ||
| pr50918.ll | ||
| pr51329.ll | ||
| pr51656.ll | ||
| preserve-gep-loop-variant.ll | ||
| related_indvars.ll | ||
| remove_indvar.ll | ||
| scaling-factor-incompat-type.ll | ||
| scaling_factor_cost_crash.ll | ||
| scev-after-loopinstsimplify.ll | ||
| scev-expander-lcssa.ll | ||
| scev-insertpt-bug.ll | ||
| sext-ind-var.ll | ||
| share_code_in_preheader.ll | ||
| share_ivs.ll | ||
| shl.ll | ||
| two-combinations-bug.ll | ||
| uglygep-address-space.ll | ||
| uglygep.ll | ||
| use_postinc_value_outside_loop.ll | ||
| var_stride_used_by_compare.ll | ||
| variable_stride.ll | ||
| wrong-hoisting-iv.ll | ||