25 lines
1.1 KiB
C
25 lines
1.1 KiB
C
/* The function below expands to a loop whose latch block starts with
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a PHI node and the corresponding debug stmt. In RTL, there are no
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PHI nodes, but the debug insn that references the incoming k
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remains, even though one of the incoming edges has it
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uninitialized. After unrolling, however, the debug insn becomes
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unconditional, and this exposed a problem in the webizer. Because
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DF doesn't combine the uses of an uninitialized pseudo into a
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single UD chain, we created a separate web for each use.
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Allocating separate registers or stack slots for each uninitialized
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use is wasteful, but the problem became more apparent in
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-fcompare-debug tests: register numbers went out of sync, and could
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have caused codegen differences depending on whether or not the
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debug insns were present. The fix was to arrange for web to
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combine uninitialized uses into a single web. */
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/* { dg-do compile } */
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/* { dg-options "-g -O1 -funroll-loops -fcompare-debug" } */
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/* { dg-xfail-if "AIX compare debug" { powerpc-ibm-aix* } } */
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void foo()
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{
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unsigned k;
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while (--k > 0);
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}
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