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0547d81fdb
latency for certain models of the Intel Atom family, by converting instructions into their equivalent LEA instructions, when it is both useful and possible to do so. llvm-svn: 180573
39 lines
1.1 KiB
LLVM
39 lines
1.1 KiB
LLVM
; RUN: llc < %s -mcpu=atom -mtriple=i686-linux | FileCheck %s
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; CHECK: addl
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; CHECK-NEXT:leal
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; CHECK-NEXT:decl
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; CHECK-NEXT:jne
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; Test for the FixupLEAs pre-emit pass. An LEA should be substituted for the ADD
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; that increments the array pointer because it is within 5 instructions of the
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; corresponding load. The ADD precedes the load by following the loop back edge.
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; Original C code
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;int test(int n, int * array)
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;{
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; int sum = 0;
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; for(int i = 0; i < n; i++)
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; sum += array[i];
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; return sum;
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;}
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define i32 @test(i32 %n, i32* nocapture %array) {
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entry:
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%cmp4 = icmp sgt i32 %n, 0
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br i1 %cmp4, label %for.body, label %for.end
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for.body:
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%i.06 = phi i32 [ %inc, %for.body ], [ 0, %entry ]
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%sum.05 = phi i32 [ %add, %for.body ], [ 0, %entry ]
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%arrayidx = getelementptr inbounds i32* %array, i32 %i.06
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%0 = load i32* %arrayidx, align 4
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%add = add nsw i32 %0, %sum.05
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%inc = add nsw i32 %i.06, 1
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%exitcond = icmp eq i32 %inc, %n
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br i1 %exitcond, label %for.end, label %for.body
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for.end:
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%sum.0.lcssa = phi i32 [ 0, %entry ], [ %add, %for.body ]
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ret i32 %sum.0.lcssa
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}
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