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