The change to "assignment not used" breaks symmetry with
"used and not set" and removes the reference to the
specific warning mentioned in /sys/doc/comp.ms.
Also, the patch was half-assed as that it left some typos
in like "used an not set", which this change also fixed.
The expression value of the assignment operation was
returned implicitely by relying on regalloc() on the
right hand side "nod" borrowing the register from nn.
But this only works if nn is a register.
In case of 6c, it can also be a ONAME from a .safe
rathole returned by regsalloc().
This change adds explicit gmove() calls to assign the
expression value. Note that gmove() checks if source
and destination are the same register so it wont emit
redundant move operations in the common case.
The same is applied also to OPREINC and OPOSTINC operations.
for gethunk() to work, all allocators have to use it,
including allocations done by libc thru malloc(),
so the fake allocation functions are mandatory for
everyone.
to avoid duplication the code is moved to cc/compat
and prototypes provided in new cc/compat.h header.
implicit casts would cause spurious "result of operation not used"
warnings such as ape's stdio putc() macro.
make (void) casts non-ops when the casted expression has no
side effects. this avoid spurious warning with ape's assert()
macro.
this fixes the miscompilation of 6l with 5c resulting in bogus
vlong -> long conversion at the top of asmandsz():
asmandsz 0x0000aec4 MOVW.W R14,#-0x2c(R13)
asmandsz+0x4 0x0000aec8 MOVW rex+8(FP),R5
asmandsz+0x8 0x0000aecc MOVW $andptr-SB(SB),R7
asmandsz+0xc 0x0000aed0 MOVW R0,R6
asmandsz+0x10 0x0000aed4 AND $#0x44,R5,R8
asmandsz+0x14 0x0000aed8 MOVW R8,rex+8(FP)
asmandsz+0x18 0x0000aedc MOVW R0,R4
asmandsz+0x1c 0x0000aee0 MOVM.IA (R0),[R1,R3] <- R1 used here
asmandsz+0x20 0x0000aee4 MOVW R8,v-4(SP) <- substituted by R8
we used to not sign extend if the destination was unsigned
uvlong, which is wrong. we have to sign extend only based
on the signedness of the source (it gets propagated to vlong)
this bug hit in hjfs in the newentry() function, causing file
creation to fail with "create -- phase error":
newentry(...)
{
uvlong sj;
int si;
...
sj = si = -1;
...
}
- cover more cases that have no side effects
- ensure function has complex FNX
- pull operators out of OFUNC level
- rewrite OSTRUCT lhs to avoid all side-effects, use regalloc() instead of regret()
On ARM, it turns out that comparisons with NaN can be made to do the
right thing with no code penalty, by a more careful selection of
condition code values in the subsequent conditional branch. The
meaning of the CC bits in the PSR is subtly different when they've
been copied from the floating point status register.
Suggested patch is 5c-nan-cmp (works on both vfp and emulated arm7500).
the integer division instructions are emulated with _div()
function patched in by 5l which does not handle conditional
execution. so do not optimize away the branch in that case.
