digitalmars.D.bugs - [Issue 3914] New: Struct as argument that fits in register has member accessed wrong
- d-bugmail puremagic.com (72/72) Mar 09 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3914
- d-bugmail puremagic.com (9/9) Mar 10 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3914
- d-bugmail puremagic.com (29/29) Mar 11 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3914
- d-bugmail puremagic.com (47/47) Mar 12 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3914
- d-bugmail puremagic.com (10/10) Mar 12 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3914
- d-bugmail puremagic.com (11/11) Apr 09 2010 http://d.puremagic.com/issues/show_bug.cgi?id=3914
http://d.puremagic.com/issues/show_bug.cgi?id=3914 Summary: Struct as argument that fits in register has member accessed wrong Product: D Version: 2.041 Platform: x86 OS/Version: Windows Status: NEW Severity: normal Priority: P2 Component: DMD AssignedTo: nobody puremagic.com ReportedBy: crimson.magus gmail.com PST --- Depending on the build options and where in a function the struct parameter is used, referencing one member will actually reference another one. Given the following program: import std.stdio; struct SS { char a; char b; char c; char d; // char e; } void A( SS ss1 ) { C: //writeln( ss1.a, ss1.b, ss1.c, ss1.d ); char temp; temp = ss1.a; ss1.a = ss1.d; ss1.d = temp; temp = ss1.b; ss1.b = ss1.c; ss1.c = temp; B: //writeln( ss1.a, ss1.b, ss1.c, ss1.d ); temp = ss1.a; ss1.a = ss1.d; ss1.d = temp; temp = ss1.b; ss1.b = ss1.c; ss1.c = temp; A: writeln( ss1.a, ss1.b, ss1.c, ss1.d ); } void main() { SS ss3; ss3.a = 'A'; ss3.b = 'L'; ss3.c = 'D'; ss3.d = 'O'; A( ss3 ); } If lines A, B, and C are enabled in the following pattern along with the given build options, you get these results: (none) -g -rel -rel-O -O -g -O A ALDO ALDO ALDO ALDA ALDA ALDA B, A ODLA ODLA ODLA ADLA ADLA ADLA ALDO ALDO ALDO ALDA ALDA ALDA C, B, A ALDA ALDO ALDA ALDA ALDA ALDA ODLA ODLA ODLA ODLA ODLA ODLA ALDO ALDO ALDO ALDO ALDO ALDO In particular, notice that field 'd' starts off wrong. If I uncomment field 'e', or change one of them to an int, the problem goes away. At C, "ALDO" should be printed. At B, "ODLA" should be printed. At A, "ALDO" should be printed. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Mar 09 2010
http://d.puremagic.com/issues/show_bug.cgi?id=3914 Don <clugdbug yahoo.com.au> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |clugdbug yahoo.com.au Severity|normal |critical -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Mar 10 2010
http://d.puremagic.com/issues/show_bug.cgi?id=3914 Here's a slightly reduced test case which doesn't require any compiler flags. Not a regression, fails even on DMD0.165. It's a problem with variadic function parameters and fastpar arguments. ------------ struct SS { char a, b, c, d; } void show(char[] args...) { assert(args[0]=='A'); assert(args[1]=='L'); assert(args[2]=='D'); assert(args[3]=='O'); } void A( SS ss ) { show( ss.a, ss.b, ss.c, ss.d ); } void main(){ SS ss3; ss3.a = 'A'; ss3.b = 'L'; ss3.c = 'D'; ss3.d = 'O'; A( ss3 ); } -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Mar 11 2010
http://d.puremagic.com/issues/show_bug.cgi?id=3914 Don <clugdbug yahoo.com.au> changed: What |Removed |Added ---------------------------------------------------------------------------- Keywords| |patch PATCH: The struct ss is passed in EAX. The backend wants ss.b. It sees that ss.b is already in EAX, so it doesn't reload it into AX. But AX actually contains ss.a. Solution: Disable the optimisation in cod1.loaddata() if it's a subsequent member of the struct. Index: cod1.c =================================================================== --- cod1.c (revision 413) +++ cod1.c (working copy) -3453,6 +3453,7 // See if we can use register that parameter was passed in if (regcon.params && e->EV.sp.Vsym->Sclass == SCfastpar && regcon.params & mask[e->EV.sp.Vsym->Spreg] && + !(e->Eoper == OPvar && e->EV.sp.Voffset > 0) && // Must be at the base of that variable sz <= REGSIZE) // make sure no 'paint' to a larger size happened { reg = e->EV.sp.Vsym->Spreg; ========================= Reduced test case: ========================= struct Snake { short a, b; } void venom(short dd) { assert(dd == 'B'); } void serpent( Snake ss ) { venom(ss.b); } void main(){ Snake s; s.a = 'A'; s.b = 'B'; serpent( s ); } -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Mar 12 2010
http://d.puremagic.com/issues/show_bug.cgi?id=3914 Walter Bright <bugzilla digitalmars.com> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |bugzilla digitalmars.com 21:59:21 PST --- changeset 416 -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Mar 12 2010
http://d.puremagic.com/issues/show_bug.cgi?id=3914 Don <clugdbug yahoo.com.au> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|NEW |RESOLVED Resolution| |FIXED Fixed DMD1.058 and DMD2.042. -- Configure issuemail: http://d.puremagic.com/issues/userprefs.cgi?tab=email ------- You are receiving this mail because: -------
Apr 09 2010