101 lines · plain
1; REQUIRES: asserts2; RUN: opt -S -passes=loop-vectorize -force-vector-width=4 -force-vector-interleave=1 -enable-interleaved-mem-accesses=true -debug-only=loop-accesses < %s 2>&1 | FileCheck %s3 4target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"5 6; Check that the compile-time-unknown depenendece-distance is resolved 7; statically. Due to the non-unit stride of the accesses in this testcase8; we are currently not able to create runtime dependence checks, and therefore9; if we don't resolve the dependence statically we cannot vectorize the loop.10;11; Specifically in this example, during dependence analysis we get 6 unknown 12; dependence distances between the 8 real/imaginary accesses below: 13; dist = 8*D, 4+8*D, -4+8*D, -8*D, 4-8*D, -4-8*D.14; At compile time we can prove for all of the above that |dist|>loopBound*step15; (where the step is 8bytes, and the loopBound is D-1), and thereby conclude 16; that there are no dependencies (without runtime tests):17; |8*D|>8*D-8, |4+8*D|>8*D-8, |-4+8*D|>8*D-8, etc.18 19; #include <stdlib.h>20; class Complex {21; private:22; float real_;23; float imaginary_;24;25; public:26; Complex() : real_(0), imaginary_(0) { }27; Complex(float real, float imaginary) : real_(real), imaginary_(imaginary) { }28; Complex(const Complex &rhs) : real_(rhs.real()), imaginary_(rhs.imaginary()) { }29; 30; inline float real() const { return real_; }31; inline float imaginary() const { return imaginary_; }32; 33; Complex operator+(const Complex& rhs) const34; {35; return Complex(real_ + rhs.real_, imaginary_ + rhs.imaginary_);36; }37;38; Complex operator-(const Complex& rhs) const39; {40; return Complex(real_ - rhs.real_, imaginary_ - rhs.imaginary_);41; }42; };43;44; void Test(Complex *out, size_t size)45; {46; size_t D = size / 2;47; for (size_t offset = 0; offset < D; ++offset)48; {49; Complex t0 = out[offset];50; Complex t1 = out[offset + D];51; out[offset] = t1 + t0;52; out[offset + D] = t0 - t1;53; }54; }55 56; CHECK-LABEL: Test57; CHECK: LAA: No unsafe dependent memory operations in loop. We don't need runtime memory checks.58; CHECK: vector.body:59; CHECK: <4 x i32>60 61%class.Complex = type { float, float }62 63define void @Test(ptr nocapture %out, i64 %size) local_unnamed_addr {64entry:65 %div = lshr i64 %size, 166 %cmp47 = icmp eq i64 %div, 067 br i1 %cmp47, label %for.cond.cleanup, label %for.body.preheader68 69for.body.preheader:70 br label %for.body71 72for.cond.cleanup.loopexit:73 br label %for.cond.cleanup74 75for.cond.cleanup:76 ret void77 78for.body:79 %offset.048 = phi i64 [ %inc, %for.body ], [ 0, %for.body.preheader ]80 %0 = getelementptr inbounds %class.Complex, ptr %out, i64 %offset.048, i32 081 %1 = load float, ptr %0, align 482 %imaginary_.i.i = getelementptr inbounds %class.Complex, ptr %out, i64 %offset.048, i32 183 %2 = load float, ptr %imaginary_.i.i, align 484 %add = add nuw i64 %offset.048, %div85 %3 = getelementptr inbounds %class.Complex, ptr %out, i64 %add, i32 086 %4 = load float, ptr %3, align 487 %imaginary_.i.i28 = getelementptr inbounds %class.Complex, ptr %out, i64 %add, i32 188 %5 = load float, ptr %imaginary_.i.i28, align 489 %add.i = fadd fast float %4, %190 %add4.i = fadd fast float %5, %291 store float %add.i, ptr %0, align 492 store float %add4.i, ptr %imaginary_.i.i, align 493 %sub.i = fsub fast float %1, %494 %sub4.i = fsub fast float %2, %595 store float %sub.i, ptr %3, align 496 store float %sub4.i, ptr %imaginary_.i.i28, align 497 %inc = add nuw nsw i64 %offset.048, 198 %exitcond = icmp eq i64 %inc, %div99 br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body100}101