Mips32 code as Mips16 unless it can't be compiled as Mips 16. For now this
would happen as long as floating point instructions are not needed.
Probably it would also make sense to compile as mips32 if atomic operations
are needed too. There may be other cases too.
A module pass prescans the IR and adds the mips16 or nomips16 attribute
to functions depending on the functions needs.
Mips 16 mode can result in a 40% code compression by utililizing 16 bit
encoding of many instructions.
The hope is for this to replace the traditional gcc way of dealing with
Mips16 code using floating point which involves essentially using soft float
but with a library implemented using mips32 floating point. This gcc
method also requires creating stubs so that Mips32 code can interact with
these Mips 16 functions that have floating point needs. My conjecture is
that in reality this traditional gcc method would never win over this
new method.
I will be implementing the traditional gcc method also. Some of it is already
done but I needed to do the stubs to finish the work and those required
this mips16/32 mixed mode capability.
I have more ideas for to make this new method much better and I think the old
method will just live in llvm for anyone that needs the backward compatibility
but I don't for what reason that would be needed.
llvm-svn: 179185
Modifier 'D' is to use the second word of a double integer.
We had previously implemented the pure register varient of
the modifier and this patch implements the memory reference.
#include "stdio.h"
int b[8] = {0,1,2,3,4,5,6,7};
void main()
{
int i;
// The first word. Notice, no 'D'
{asm (
"lw %0,%1;"
: "=r" (i)
: "m" (*(b+4))
);}
printf("%d\n",i);
// The second word
{asm (
"lw %0,%D1;"
: "=r" (i)
: "m" (*(b+4))
);}
printf("%d\n",i);
}
llvm-svn: 179135
and mips16 on a per function basis.
Because this patch is somewhat involved I have provide an overview of the
key pieces of it.
The patch is written so as to not change the behavior of the non mixed
mode. We have tested this a lot but it is something new to switch subtargets
so we don't want any chance of regression in the mainline compiler until
we have more confidence in this.
Mips32/64 are very different from Mip16 as is the case of ARM vs Thumb1.
For that reason there are derived versions of the register info, frame info,
instruction info and instruction selection classes.
Now we register three separate passes for instruction selection.
One which is used to switch subtargets (MipsModuleISelDAGToDAG.cpp) and then
one for each of the current subtargets (Mips16ISelDAGToDAG.cpp and
MipsSEISelDAGToDAG.cpp).
When the ModuleISel pass runs, it determines if there is a need to switch
subtargets and if so, the owning pointers in MipsTargetMachine are
appropriately changed.
When 16Isel or SEIsel is run, they will return immediately without doing
any work if the current subtarget mode does not apply to them.
In addition, MipsAsmPrinter needs to be reset on a function basis.
The pass BasicTargetTransformInfo is substituted with a null pass since the
pass is immutable and really needs to be a function pass for it to be
used with changing subtargets. This will be fixed in a follow on patch.
llvm-svn: 179118
This patch initializes t9 to the handler address, but only if the relocation
model is pic. This handles the case where handler to which eh.return jumps
points to the start of the function.
Patch by Sasa Stankovic.
llvm-svn: 178588
derived class MipsSETargetLowering.
We shouldn't be generating madd/msub nodes if target is Mips16, since Mips16
doesn't have support for multipy-add/sub instructions.
llvm-svn: 178404
Apparently my final cleanup to use a relevant suffix for these tests before
committing r176831 caused them to stop running since lit wasn't configured to
run tests with that suffix in those directories (why don't we just have a
global suffix list?). So, add the suffix to the relevant directories & fix the
test that has bitrotted over the last week due to my debug info schema changes.
llvm-svn: 177315
This calling convention was added just to handle functions which return vector
of floats. The fix committed in r165585 solves the problem.
llvm-svn: 176530
This patch eliminates the need to emit a constant move instruction when this
pattern is matched:
(select (setgt a, Constant), T, F)
The pattern above effectively turns into this:
(conditional-move (setlt a, Constant + 1), F, T)
llvm-svn: 176384
SltCCRxRy16, SltiCCRxImmX16, SltiuCCRxImmX16, SltuCCRxRy16
$T8 shows up as register $24 when emitted from C++ code so we had
to change some tests that were already there for this functionality.
llvm-svn: 175593
This expansion will be moved to expandISelPseudos as soon as I can figure
out how to do that. There are other instructions which use this
ExpandFEXT_T8I816_ins and as soon as I have finished expanding them all,
I will delete the macro asm string text so it has no way to be used
in the future.
llvm-svn: 175413
not matter but makes it more gcc compatible which avoids possible subtle
problems. Also, turned back on a disabled check in helloworld.ll.
llvm-svn: 175237
if the offset fits in 11 bits. This makes use of the fact that the abi
requires sp to be 8 byte aligned so the actual offset can fit in 8
bits. It will be shifted left and sign extended before being actually used.
The assembler or direct object emitter will shift right the 11 bit
signed field by 3 bits. We don't need to deal with that here.
llvm-svn: 175073
