| Message ID | f7abb6b2-1be2-21ad-979b-980dbfe177d3@vnet.ibm.com |
|---|---|
| State | New |
| Headers | show |
On May 23, 2017 7:46:59 PM GMT+02:00, Peter Bergner <bergner@vnet.ibm.com> wrote: >The fix for PR80775 included a thinko bug that caused us to skip some >case label statements. This leads to problems for test cases where we >have multiple case labels that point to the same unreachable block, but >are not mergeable since they don't have consecutive case values. >This leads to a problem, because we remove the unreachable block when >handling this first case label, but then we have a dangling reference >to that block with the skipped case label. The fix is to remove the >unwanted increment, so that we handle the next case label and end up >removing it too. > >This passed bootstrap and regtesting on powerpc64le-linux with no >regressions. Is this ok for trunk? OK. Richard. >Peter > >gcc/ > PR middle-end/80823 > * tree-cfg.c (group_case_labels_stmt): Delete increment of "i"; > >gcc/testsuite/ > PR middle-end/80823 > * gcc.dg/pr80823.c: New test. > >Index: gcc/tree-cfg.c >=================================================================== >--- gcc/tree-cfg.c (revision 248375) >+++ gcc/tree-cfg.c (working copy) >@@ -1726,7 +1726,6 @@ group_case_labels_stmt (gswitch *stmt) > remove_edge_and_dominated_blocks (base_edge); > gimple_switch_set_label (stmt, base_index, NULL_TREE); > new_size--; >- i++; > } > } > >Index: gcc/testsuite/gcc.dg/pr80823.c >=================================================================== >--- gcc/testsuite/gcc.dg/pr80823.c (nonexistent) >+++ gcc/testsuite/gcc.dg/pr80823.c (working copy) >@@ -0,0 +1,23 @@ >+/* PR middle-end/80823 ICE: verify_flow_info failed */ >+/* { dg-do compile } */ >+/* { dg-options "-O3" } */ >+ >+int a, c; >+int b[1]; >+static inline int >+fn1() { >+ switch (a) >+ case 0: >+ case 2: >+ return 1; >+ return 0; >+} >+void fn2() { >+ int i; >+ for (;; ++i) { >+ c = b[i]; >+ int d = !fn1(); >+ if (d) >+ __asm__(""); >+ } >+}
On 5/24/17 2:15 AM, Richard Biener wrote: > On May 23, 2017 7:46:59 PM GMT+02:00, Peter Bergner <bergner@vnet.ibm.com> wrote: >> gcc/ >> PR middle-end/80823 >> * tree-cfg.c (group_case_labels_stmt): Delete increment of "i"; >> >> gcc/testsuite/ >> PR middle-end/80823 >> * gcc.dg/pr80823.c: New test. > > OK. > Thanks, committed as revision 248408. Peter
Index: gcc/tree-cfg.c =================================================================== --- gcc/tree-cfg.c (revision 248375) +++ gcc/tree-cfg.c (working copy) @@ -1726,7 +1726,6 @@ group_case_labels_stmt (gswitch *stmt) remove_edge_and_dominated_blocks (base_edge); gimple_switch_set_label (stmt, base_index, NULL_TREE); new_size--; - i++; } } Index: gcc/testsuite/gcc.dg/pr80823.c =================================================================== --- gcc/testsuite/gcc.dg/pr80823.c (nonexistent) +++ gcc/testsuite/gcc.dg/pr80823.c (working copy) @@ -0,0 +1,23 @@ +/* PR middle-end/80823 ICE: verify_flow_info failed */ +/* { dg-do compile } */ +/* { dg-options "-O3" } */ + +int a, c; +int b[1]; +static inline int +fn1() { + switch (a) + case 0: + case 2: + return 1; + return 0; +} +void fn2() { + int i; + for (;; ++i) { + c = b[i]; + int d = !fn1(); + if (d) + __asm__(""); + } +}