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