[Issue 17940] bool function parameters loaded from struct sometimes miscompiled with -O
https://issues.dlang.org/show_bug.cgi?id=17940
FeepingCreature changed:
What|Removed |Added
CC||default_357-l...@yahoo.de
--- Comment #1 from FeepingCreature ---
Simplified a bit:
struct Array
{
long length, ptr;
}
struct Struct
{
bool b = true;
}
void fun1(int) { }
void fun2(Array arr, int, int)
{
assert(!arr.length);
}
void fn(Struct* str)
{
Array arr;
if (!str) return;
if (str)
{
fun1(str.b);
}
if (str.b)
{
fun2(arr, str.b, 0);
}
}
void main()
{
Struct s;
fn(&s);
}
--
[Issue 17940] bool function parameters loaded from struct sometimes miscompiled with -O
https://issues.dlang.org/show_bug.cgi?id=17940 --- Comment #2 from FeepingCreature --- Hah! It tries to reload the cse into ESI, but since that's a 1-byte operation (since bool), it actually becomes a move to DH. ESI is not even reachable with 1-byte ops, because those register values were used to address high regs. So for reg8 opcodes like 0x8A, code->setReg should assert on reg & 4. How to actually fix this though, no idea. --
[Issue 17940] bool function parameters loaded from struct sometimes miscompiled with -O
https://issues.dlang.org/show_bug.cgi?id=17940 --- Comment #3 from FeepingCreature --- Proposed fix: https://github.com/dlang/dmd/pull/7252 --
[Issue 17940] bool function parameters loaded from struct sometimes miscompiled with -O
https://issues.dlang.org/show_bug.cgi?id=17940 --- Comment #4 from github-bugzi...@puremagic.com --- Commits pushed to master at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/87cd61e4c4aca33254bacb2af735433193a51039 fix issue 17940 When generating a 1-byte mov cse on x86_64, handle the REX flag after setReg, instead of when the instruction is first created, since that's when we know if we need it. https://github.com/dlang/dmd/commit/89b0af132529d4635717fd4b16ffc300056dd1b9 Merge pull request #7252 from FeepingCreature/master fix issue 17940 - always set REX for 1-byte CSE moves on x86_64 merged-on-behalf-of: Walter Bright --
[Issue 17940] bool function parameters loaded from struct sometimes miscompiled with -O
https://issues.dlang.org/show_bug.cgi?id=17940 github-bugzi...@puremagic.com changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --
[Issue 17940] bool function parameters loaded from struct sometimes miscompiled with -O
https://issues.dlang.org/show_bug.cgi?id=17940 --- Comment #5 from github-bugzi...@puremagic.com --- Commits pushed to stable at https://github.com/dlang/dmd https://github.com/dlang/dmd/commit/87cd61e4c4aca33254bacb2af735433193a51039 fix issue 17940 https://github.com/dlang/dmd/commit/89b0af132529d4635717fd4b16ffc300056dd1b9 Merge pull request #7252 from FeepingCreature/master --
