forked from OSchip/llvm-project
99 lines
3.4 KiB
LLVM
99 lines
3.4 KiB
LLVM
; RUN: opt -passes='print-access-info' -disable-output < %s 2>&1 | FileCheck %s
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target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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; Check that the compile-time-unknown depenendece-distance is resolved
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; statically. Due to the non-unit stride of the accesses in this testcase
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; we are currently not able to create runtime dependence checks, and therefore
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; if we don't resolve the dependence statically we cannot vectorize the loop.
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;
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; Specifically in this example, during dependence analysis we get 6 unknown
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; dependence distances between the 8 real/imaginary accesses below:
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; dist = 8*D, 4+8*D, -4+8*D, -8*D, 4-8*D, -4-8*D.
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; At compile time we can prove for all of the above that |dist|>loopBound*step
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; (where the step is 8bytes, and the loopBound is D-1), and thereby conclude
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; that there are no dependencies (without runtime tests):
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; |8*D|>8*D-8, |4+8*D|>8*D-8, |-4+8*D|>8*D-8, etc.
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; #include <stdlib.h>
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; class Complex {
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; private:
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; float real_;
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; float imaginary_;
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;
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; public:
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; Complex() : real_(0), imaginary_(0) { }
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; Complex(float real, float imaginary) : real_(real), imaginary_(imaginary) { }
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; Complex(const Complex &rhs) : real_(rhs.real()), imaginary_(rhs.imaginary()) { }
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;
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; inline float real() const { return real_; }
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; inline float imaginary() const { return imaginary_; }
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;
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; Complex operator+(const Complex& rhs) const
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; {
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; return Complex(real_ + rhs.real_, imaginary_ + rhs.imaginary_);
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; }
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;
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; Complex operator-(const Complex& rhs) const
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; {
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; return Complex(real_ - rhs.real_, imaginary_ - rhs.imaginary_);
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; }
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; };
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;
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; void Test(Complex *out, size_t size)
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; {
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; size_t D = size / 2;
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; for (size_t offset = 0; offset < D; ++offset)
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; {
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; Complex t0 = out[offset];
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; Complex t1 = out[offset + D];
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; out[offset] = t1 + t0;
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; out[offset + D] = t0 - t1;
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; }
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; }
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; CHECK-LABEL: Test
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; CHECK: Memory dependences are safe
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%class.Complex = type { float, float }
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define void @Test(%class.Complex* nocapture %out, i64 %size) local_unnamed_addr {
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entry:
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%div = lshr i64 %size, 1
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%cmp47 = icmp eq i64 %div, 0
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br i1 %cmp47, label %for.cond.cleanup, label %for.body.preheader
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for.body.preheader:
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br label %for.body
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for.cond.cleanup.loopexit:
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br label %for.cond.cleanup
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for.cond.cleanup:
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ret void
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for.body:
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%offset.048 = phi i64 [ %inc, %for.body ], [ 0, %for.body.preheader ]
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%0 = getelementptr inbounds %class.Complex, %class.Complex* %out, i64 %offset.048, i32 0
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%1 = load float, float* %0, align 4
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%imaginary_.i.i = getelementptr inbounds %class.Complex, %class.Complex* %out, i64 %offset.048, i32 1
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%2 = load float, float* %imaginary_.i.i, align 4
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%add = add nuw i64 %offset.048, %div
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%3 = getelementptr inbounds %class.Complex, %class.Complex* %out, i64 %add, i32 0
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%4 = load float, float* %3, align 4
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%imaginary_.i.i28 = getelementptr inbounds %class.Complex, %class.Complex* %out, i64 %add, i32 1
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%5 = load float, float* %imaginary_.i.i28, align 4
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%add.i = fadd fast float %4, %1
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%add4.i = fadd fast float %5, %2
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store float %add.i, float* %0, align 4
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store float %add4.i, float* %imaginary_.i.i, align 4
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%sub.i = fsub fast float %1, %4
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%sub4.i = fsub fast float %2, %5
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store float %sub.i, float* %3, align 4
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store float %sub4.i, float* %imaginary_.i.i28, align 4
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%inc = add nuw nsw i64 %offset.048, 1
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%exitcond = icmp eq i64 %inc, %div
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br i1 %exitcond, label %for.cond.cleanup.loopexit, label %for.body
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}
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