Commit Graph

6 Commits

Author SHA1 Message Date
Adhemerval Zanella a3cefa5d64 [AArch64] Optimize floating point materialization
This patch follows some ideas from r352866 to optimize the floating
point materialization even further. It changes isFPImmLegal to
considere up to 2 mov instruction or up to 5 in case subtarget has
fused literals.

The rationale is the cost is the same for mov+fmov vs. adrp+ldr; but
the mov+fmov sequence is always better because of the reduced d-cache
pressure. The timings are still the same if you consider movw+movk+fmov
vs. adrp+ldr will be fused (although one instruction longer).

Reviewers: efriedma

Differential Revision: https://reviews.llvm.org/D58460

llvm-svn: 356390
2019-03-18 18:45:57 +00:00
Adhemerval Zanella b3ccc5550d [AArch64] Optimize floating point materialization
This patch changes isFPImmLegal to return if the value can be enconded
as the immediate operand of a logical instruction besides checking if
for immediate field for fmov.

This optimizes some floating point materization, inclusive values
used on isinf lowering.

Reviewed By: rengolin, efriedma, evandro

Differential Revision: https://reviews.llvm.org/D57044

llvm-svn: 352866
2019-02-01 12:26:06 +00:00
Martin Storsjo 9dafd6f6d9 Revert "[COFF] Use comdat shared constants for MinGW as well"
This reverts commit r337951.

While that kind of shared constant generally works fine in a MinGW
setting, it broke some cases of inline assembly that worked before:

$ cat const-asm.c
int MULH(int a, int b) {
    int rt, dummy;
    __asm__ (
        "imull %3"
        :"=d"(rt), "=a"(dummy)
        :"a"(a), "rm"(b)
    );
    return rt;
}
int func(int a) {
    return MULH(a, 1);
}
$ clang -target x86_64-win32-gnu -c const-asm.c -O2
const-asm.c:4:9: error: invalid variant '00000001'
        "imull %3"
        ^
<inline asm>:1:15: note: instantiated into assembly here
        imull __real@00000001(%rip)
                     ^

A similar error is produced for i686 as well. The same test with a
target of x86_64-win32-msvc or i686-win32-msvc works fine.

llvm-svn: 338018
2018-07-26 10:48:20 +00:00
Martin Storsjo ff33a95ed4 [COFF] Use comdat shared constants for MinGW as well
GNU binutils tools have no problems with this kind of shared constants,
provided that we actually hook it up completely in AsmPrinter and
produce a global symbol.

This effectively reverts SVN r335918 by hooking the rest of it up
properly.

This feature was implemented originally in SVN r213006, with no reason
for why it can't be used for MinGW other than the fact that GCC doesn't
do it while MSVC does.

Differential Revision: https://reviews.llvm.org/D49646

llvm-svn: 337951
2018-07-25 18:35:42 +00:00
Martin Storsjo d2662c32fb [COFF] Hoist constant pool handling from X86AsmPrinter into AsmPrinter
In SVN r334523, the first half of comdat constant pool handling was
hoisted from X86WindowsTargetObjectFile (which despite the name only
was used for msvc targets) into the arch independent
TargetLoweringObjectFileCOFF, but the other half of the handling was
left behind in X86AsmPrinter::GetCPISymbol.

With only half of the handling in place, inconsistent comdat
sections/symbols are created, causing issues with both GNU binutils
(avoided for X86 in SVN r335918) and with the MS linker, which
would complain like this:

fatal error LNK1143: invalid or corrupt file: no symbol for COMDAT section 0x4

Differential Revision: https://reviews.llvm.org/D49644

llvm-svn: 337950
2018-07-25 18:35:31 +00:00
Martin Storsjo c2b701408e [AArch64] Use MCAsmInfoMicrosoft and MCAsmInfoGNUCOFF as base classes
This matches the structure used on X86 and ARM. This requires
a little bit of duplication of the parts that are equal in both
AArch64 COFF variants though.

Before SVN r335286, these classes didn't add anything that MCAsmInfoCOFF
didn't, but now they do.

This makes AArch64 match X86 in how comdat is used for float constants
for MinGW.

Differential Revision: https://reviews.llvm.org/D49637

llvm-svn: 337755
2018-07-23 22:15:14 +00:00