That is, "clang -ftrapv" builds don't abort almost immediately after entering
a level.
There are various classes of overflow bugs, needing different handling:
- Some texture mapping code was written with signed integer wrapping semantics
in mind. In some places, we're able to get away with unsigned casts.
- sometimes, we really need a wider range, like when calculating distances or
dot products
- negating INT_MIN. Here, we cast to int64_t temporarily. Note that if the
result is 32-bit wide, no 64-bit code may actually need to be generated.
- shifting into a signed integer's sign bit. We cast to uint32 here.
- in hitscan(), at the "abyss crash prevention code" comment, it's clearly
the other code that is better...
This is not merely done for pedantry, but rather makes it easier to track down
overflow bugs having a real impact on the game.
git-svn-id: https://svn.eduke32.com/eduke32@2784 1a8010ca-5511-0410-912e-c29ae57300e0
The original patch was communicated to me by Hendricks, but since it didn't
apply cleanly (it's based on r2182) I took the liberty of slightly messing
with it for inclusion into EDuke32.
Info: http://wiibrew.org/wiki/User:Tueidj/Duke3D
This first part (which wasn't changed from the original patch) implements
scaling arithmetic and miscellaneous pragmas, some in PPC assembly and a part
of them in C. Of some interest is the fact that the Wii processor apparently
lacks support for 64-bit integers, so divscale() uses floating-point math.
git-svn-id: https://svn.eduke32.com/eduke32@2621 1a8010ca-5511-0410-912e-c29ae57300e0
With the same setup as before, a screen-filling translucent wall (with nothing
drawn behind it) renders at about 7 fps faster (from 60-something fps initially)
git-svn-id: https://svn.eduke32.com/eduke32@2498 1a8010ca-5511-0410-912e-c29ae57300e0
These two functions draw a vertical line 4 neighboring pixels at a time.
This gives a significant speed boost for a full screen solid and masked wall
scene for x86_64 (where we have plenty of registers), about 60 --> 76 fps.
git-svn-id: https://svn.eduke32.com/eduke32@2497 1a8010ca-5511-0410-912e-c29ae57300e0
- forgot a glogy --> logy in a-c.c
- comment out stretchhline and slopevlin2 in a.nasm, the former also in a-c.c
- make transmaskvline2 use a uintptr_t where appropriate
git-svn-id: https://svn.eduke32.com/eduke32@2448 1a8010ca-5511-0410-912e-c29ae57300e0
Hlines for masked and translucent masked ceiling/floor (sprites).
- apply the --> 'do { ... } while (--cnt)' transformation, making these
functions iterate cnt+1 times like the asm version. This also fixes an
off-by-one issue where sprites or masked ceilings/floors had a one-pixel
non-drawn line to the right.
- This time, only declare-as-local two 'extern' globals (asm1 and asm2).
It seems that I was too eager with "localing" all file-scoped vars earlier.
GCC is able to remove the loads from memory inside the loop by itself, whereas
clang is not. This is not trivial, since it has to prove that the 'screen'
pointer passed to the functions will never alias these globals.
git-svn-id: https://svn.eduke32.com/eduke32@2424 1a8010ca-5511-0410-912e-c29ae57300e0
Affected functions: hlineasm4, vlineasm1, mvlineasm1, tvlineasm1.
Optimizations:
- declare all used variables as possibly const-qualified locals in each
function. This removes unnecessary loads from memory in the loops.
- rewrite "for (; cnt>=0; cnt--) {...}" to "cnt++; do {...} while (--cnt);"
in the three last ones (yes, these function iterate cnt+1 times). This
makes them functionally equivalent to the asm versions (madness ensues for
cnt < 0) and allows the compiler to remove one 'test' instruction at the
end of each loop.
- in the translucence function, replace addition by ORing
Observations (system: Core2 Duo Linux x86_64):
With a 1680x1050 window fully covered by the respective type of wall (simple,
masked, trans. masked), fps increases by 3-4 from the baseline of approx. 60.
git-svn-id: https://svn.eduke32.com/eduke32@2405 1a8010ca-5511-0410-912e-c29ae57300e0
* Sprite cstat 2048 ('use own shade', [N]) now works more or less. (Issues may arise when combined with sector light effects.)
* Begin work on 'smart' tag labeling system for Mapster32. Right now, it only displays a '+' after tags with linking semantics.
*
git-svn-id: https://svn.eduke32.com/eduke32@1866 1a8010ca-5511-0410-912e-c29ae57300e0
