101 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			LLVM
		
	
	
	
			
		
		
	
	
			101 lines
		
	
	
		
			3.6 KiB
		
	
	
	
		
			LLVM
		
	
	
	
| ; REQUIRES: asserts
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| ; RUN: opt -S -loop-vectorize -force-vector-width=4 -force-vector-interleave=1 -enable-interleaved-mem-accesses=true -debug-only=loop-accesses < %s  2>&1 | FileCheck %s
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| 
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| target datalayout = "e-m:e-i64:64-f80:128-n8:16:32:64-S128"
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| 
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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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| 
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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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| 
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| ; CHECK-LABEL: Test
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| ; CHECK: LAA: No unsafe dependent memory operations in loop.  We don't need runtime memory checks.
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| ; CHECK: vector.body:
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| ; CHECK: <4 x i32>
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| 
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| %class.Complex = type { float, float }
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| 
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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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| 
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| for.body.preheader:
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|   br label %for.body
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| 
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| for.cond.cleanup.loopexit:
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|   br label %for.cond.cleanup
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| 
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| for.cond.cleanup:
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|   ret void
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| 
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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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