llvm-6502/test/Transforms/LoopVectorize/runtime-check.ll
Arnold Schwaighofer 0097e15502 LoopVectorizer: If dependency checks fail try runtime checks
When a dependence check fails we can still try to vectorize loops with runtime
array bounds checks.

This helps linpack to vectorize a loop in dgefa. And we are back to 2x of the
scalar performance on a corei7-avx.

radar://15339680

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193853 91177308-0d34-0410-b5e6-96231b3b80d8
2013-11-01 03:05:07 +00:00

65 lines
2.4 KiB
LLVM

; RUN: opt < %s -loop-vectorize -force-vector-unroll=1 -force-vector-width=4 -dce -instcombine -S | FileCheck %s
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64-S128"
target triple = "x86_64-apple-macosx10.9.0"
; Make sure we vectorize this loop:
; int foo(float *a, float *b, int n) {
; for (int i=0; i<n; ++i)
; a[i] = b[i] * 3;
; }
;CHECK: for.body.preheader:
;CHECK: br i1 %cmp.zero, label %middle.block, label %vector.memcheck
;CHECK: vector.memcheck:
;CHECK: br i1 %memcheck.conflict, label %middle.block, label %vector.ph
;CHECK: load <4 x float>
define i32 @foo(float* nocapture %a, float* nocapture %b, i32 %n) nounwind uwtable ssp {
entry:
%cmp6 = icmp sgt i32 %n, 0
br i1 %cmp6, label %for.body, label %for.end
for.body: ; preds = %entry, %for.body
%indvars.iv = phi i64 [ %indvars.iv.next, %for.body ], [ 0, %entry ]
%arrayidx = getelementptr inbounds float* %b, i64 %indvars.iv
%0 = load float* %arrayidx, align 4
%mul = fmul float %0, 3.000000e+00
%arrayidx2 = getelementptr inbounds float* %a, i64 %indvars.iv
store float %mul, float* %arrayidx2, align 4
%indvars.iv.next = add i64 %indvars.iv, 1
%lftr.wideiv = trunc i64 %indvars.iv.next to i32
%exitcond = icmp eq i32 %lftr.wideiv, %n
br i1 %exitcond, label %for.end, label %for.body
for.end: ; preds = %for.body, %entry
ret i32 undef
}
; Make sure that we try to vectorize loops with a runtime check if the
; dependency check fails.
; CHECK-LABEL: test_runtime_check
; CHECK: <4 x float>
define void @test_runtime_check(float* %a, float %b, i64 %offset, i64 %offset2, i64 %n) {
entry:
br label %for.body
for.body:
%iv = phi i64 [ 0, %entry ], [ %iv.next, %for.body ]
%ind.sum = add i64 %iv, %offset
%arr.idx = getelementptr inbounds float* %a, i64 %ind.sum
%l1 = load float* %arr.idx, align 4
%ind.sum2 = add i64 %iv, %offset2
%arr.idx2 = getelementptr inbounds float* %a, i64 %ind.sum2
%l2 = load float* %arr.idx2, align 4
%m = fmul fast float %b, %l2
%ad = fadd fast float %l1, %m
store float %ad, float* %arr.idx, align 4
%iv.next = add nuw nsw i64 %iv, 1
%exitcond = icmp eq i64 %iv.next, %n
br i1 %exitcond, label %loopexit, label %for.body
loopexit:
ret void
}