I thought there is a bit in the symbol table that tells whether the symbol is uplevel ref. Your method seemed to be a hack Sun
On Mon, Dec 20, 2010 at 7:25 PM, Jiangzhou HE <hejiangz...@gmail.com> wrote: > Hi, > > Can a gatekeeper help to review the patch to bug 702 > (https://bugs.open64.net/show_bug.cgi?id=702) > > This is the test case: > > #include <stdio.h> > > void foo(int x) { > > > void far() { > x++; > > } > > void bar() { > > int x2 = x; > far(); > > printf("%d %d\n", x, x2); > } > > > bar(); > } > > > int main() { > foo(1); > > return 0; > } > > This is a bug of alias classifying. Because of this bug, in bar(), the > variable x is treated as a local variable in current PU, so x gets an own > class ID. Therefore, in the call site for far(), no CHI node is created for > x. Then, by copy propagation, the last argument of printf() is replaced by > x. Then we can see the wrong output. > > This is the buggy code: > > // If this base_id is a local variable or parameter, it gets its > // own class. > if ((storage_class == SCLASS_AUTO && > ST_IDX_level(ST_st_idx(st)) == CURRENT_SYMTAB) || > storage_class == SCLASS_FORMAL || > storage_class == SCLASS_FORMAL_REF || > storage_class == SCLASS_REG) { > // Set up the LDA and LDID classes for this variable... > > It checks whether the symbol is in current level for auto variables, but > does not check for formals. I fix the bug in this way: > > diff --git a/osprey/be/opt/opt_alias_class.cxx > b/osprey/be/opt/opt_alias_class.cxx > index d4ebc6f..42db9b2 100644 > --- a/osprey/be/opt/opt_alias_class.cxx > +++ b/osprey/be/opt/opt_alias_class.cxx > @@ -409,10 +409,10 @@ ALIAS_CLASSIFICATION::New_base_id(const ST *st, TY_IDX > ty) > > // If this base_id is a local variable or parameter, it gets its > // own class. > - if ((storage_class == SCLASS_AUTO && > + if (((storage_class == SCLASS_AUTO || > + storage_class == SCLASS_FORMAL || > + storage_class == SCLASS_FORMAL_REF) && > ST_IDX_level(ST_st_idx(st)) == CURRENT_SYMTAB) || > - storage_class == SCLASS_FORMAL || > - storage_class == SCLASS_FORMAL_REF || > storage_class == SCLASS_REG) { > // Set up the LDA and LDID classes for this variable... > ALIAS_CLASS_MEMBER *ldid_item = New_alias_class_member(id); > @@ -490,7 +490,8 @@ ALIAS_CLASSIFICATION::New_base_id(const ST *st, TY_IDX > ty) > // uplevel reference and therefore must be treated as > // global because its address can be stored into a global, > // and it may contain the address of a global. Non-uplevel > - // references with SCLASS_AUTO are handled as locals above. > + // references with SCLASS_AUTO, SCLASS_FORMAL or > + // SCLASS_FORMAL_REF are handled as locals above. > // Including uplevel references here is the fix for 555533. > // 634200 was a milder case of the same problem, and only > // part of the fix was required to get that one right; that > @@ -498,6 +499,8 @@ ALIAS_CLASSIFICATION::New_base_id(const ST *st, TY_IDX > ty) > // parameters; 555533 makes clear that we have to go > // all the way and treat them as globals. > storage_class == SCLASS_AUTO || > + storage_class == SCLASS_FORMAL || > + storage_class == SCLASS_FORMAL_REF || > // storage class can be UNKNOWN for constant data because CG may > // already have run for an earlier PU and in the process lowered > // string (and maybe other) constants to .rodata. Unfortunately, > > Thanks! > > -- > Jiangzhou HE (何江舟) > > Institute of High-Performance Computing > Department of Computer Science and Technology > Tsinghua University, Beijing, China > > > ------------------------------------------------------------------------------ > Lotusphere 2011 > Register now for Lotusphere 2011 and learn how > to connect the dots, take your collaborative environment > to the next level, and enter the era of Social Business. > http://p.sf.net/sfu/lotusphere-d2d > _______________________________________________ > Open64-devel mailing list > Open64-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/open64-devel > > ------------------------------------------------------------------------------ Lotusphere 2011 Register now for Lotusphere 2011 and learn how to connect the dots, take your collaborative environment to the next level, and enter the era of Social Business. http://p.sf.net/sfu/lotusphere-d2d _______________________________________________ Open64-devel mailing list Open64-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/open64-devel
