38 lines
1.1 KiB
C
38 lines
1.1 KiB
C
// This tests loop unrolling and loop deletion (enabled under -O1)
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// RUN: %clang_cc1 -std=c11 -O1 -fno-unroll-loops -S -o - %s -emit-llvm | FileCheck %s
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// RUN: %clang_cc1 -std=c99 -O1 -fno-unroll-loops -S -o - %s -emit-llvm | FileCheck %s --check-prefix C99
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extern int a[16];
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int b = 0;
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int foo(void) {
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#pragma unroll
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for (int i = 0; i < 16; ++i)
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a[i] = b += 2;
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return b;
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}
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// Check br i1 to make sure that the loop is fully unrolled
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// CHECK-LABEL: foo
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// CHECK-NOT: br i1
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void Helper() {
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const int *nodes[5];
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int num_active = 5;
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while (num_active)
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#pragma clang loop unroll(full)
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for (int i = 0; i < 5; ++i)
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if (nodes[i])
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--num_active;
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}
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// Check br i1 to make sure the loop is gone, there will still be a label branch for the infinite loop.
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// In C99, there was no forward progress requirement, so we expect the infinite loop to still exist,
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// but for C11 and onwards, the infinite loop can be deleted.
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// CHECK-LABEL: Helper
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// C99: br label
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// C99-NOT: br i1
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// C99: br label
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// CHECK: entry:
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// CHECK-NOT: br i1
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// CHECK-NEXT: ret void
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