This doesn't occur much at all, it only seems to formed in the case
when the trunc optimization kicks in due to phase ordering. In that
case it is saves a few bytes on x86-32.
llvm-svn: 101350
a load/or/and/store sequence into a narrower store when it is
safe. Daniel tells me that clang will start producing this sort
of thing with bitfields, and this does trigger a few dozen times
on 176.gcc produced by llvm-gcc even now.
This compiles code like CodeGen/X86/2009-05-28-DAGCombineCrash.ll
into:
movl %eax, 36(%rdi)
instead of:
movl $4294967295, %eax ## imm = 0xFFFFFFFF
andq 32(%rdi), %rax
shlq $32, %rcx
addq %rax, %rcx
movq %rcx, 32(%rdi)
and each of the testcases into a single store. Each of them used
to compile into craziness like this:
_test4:
movl $65535, %eax ## imm = 0xFFFF
andl (%rdi), %eax
shll $16, %esi
addl %eax, %esi
movl %esi, (%rdi)
ret
llvm-svn: 101343
current PC. rdar://7834775
We now produce an identical .o file compared to the cctools
assembler for something like this:
_f0:
L0:
jmp L1
.long . - L0
L1:
jmp A
.long . - L1
.zerofill __DATA,_bss,A,0
llvm-svn: 101227
This test relies on iSel lowering dbg_declare intrinsic when CodeGen::OptLevel is None. On PPC side, CodeGen::OptLevel stays to default when -O0 is used on the command line.
llvm-svn: 101190
numerator is an induction variable. For example, with code like this:
for (i=0;i<n;++i)
x[i%n] = 0;
IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the remainder.
llvm-svn: 101113
If we have this situation:
jCC L1
jmp L2
L1:
...
L2:
...
We can get a small performance boost by emitting this instead:
jnCC L2
L1:
...
L2:
...
This testcase shows an example of this:
float func(float x, float y) {
double product = (double)x * y;
if (product == 0.0)
return product;
return product - 1.0;
}
llvm-svn: 101075
expression is a UDiv and it doesn't appear that the UDiv came from
the user's source.
ScalarEvolution has recently figured out how to compute a tripcount
expression for the inner loop in
SingleSource/Benchmarks/Shootout/sieve.c, using a udiv. Emitting a
udiv instruction dramatically slows down the enclosing loop.
llvm-svn: 101068
ARM_AM::getSoImmVal(V) with a legitimate so_imm value: #245 rotate right by 2.
Introduce ARM_AM::getSOImmValOneOrNoRotate(unsigned Arg) which is called from
ARMInstPrinter.cpp's printSOImm() function, replacing ARM_AM::getSOImmVal(V).
[12:44:43] johnny:/Volumes/data/llvm/git/trunk (local-trunk) $ gdb Debug/bin/llvm-mc
GNU gdb 6.3.50-20050815 (Apple version gdb-1346) (Fri Sep 18 20:40:51 UTC 2009)
Copyright 2004 Free Software Foundation, Inc.
GDB is free software, covered by the GNU General Public License, and you are
welcome to change it and/or distribute copies of it under certain conditions.
Type "show copying" to see the conditions.
There is absolutely no warranty for GDB. Type "show warranty" for details.
This GDB was configured as "x86_64-apple-darwin"...Reading symbols for shared libraries ... done
(gdb) set args -triple=arm-apple-darwin9 -debug-only=arm-disassembler --disassemble
(gdb) r
Starting program: /Volumes/data/llvm/git/trunk/Debug/bin/llvm-mc -triple=arm-apple-darwin9 -debug-only=arm-disassembler --disassemble
Reading symbols for shared libraries ++. done
0xf5 0x71 0xf0 0x53
Opcode=201 Name=MVNi Format=ARM_FORMAT_DPFRM(4)
31 30 29 28 27 26 25 24 23 22 21 20 19 18 17 16 15 14 13 12 11 10 9 8 7 6 5 4 3 2 1 0
-------------------------------------------------------------------------------------------------
| 0: 1: 0: 1| 0: 0: 1: 1| 1: 1: 1: 1| 0: 0: 0: 0| 0: 1: 1: 1| 0: 0: 0: 1| 1: 1: 1: 1| 0: 1: 0: 1|
-------------------------------------------------------------------------------------------------
mvnpls r7, Assertion failed: (V != -1 && "Not a valid so_imm value!"), function printSOImm, file ARMInstPrinter.cpp, line 229.
Program received signal SIGABRT, Aborted.
0x00007fff88c65886 in __kill ()
(gdb) bt
#0 0x00007fff88c65886 in __kill ()
#1 0x00007fff88d05eae in abort ()
#2 0x00007fff88cf2ef0 in __assert_rtn ()
#3 0x000000010020e422 in printSOImm (O=@0x1010bdf80, V=-1, VerboseAsm=false, MAI=0x1020106d0) at ARMInstPrinter.cpp:229
#4 0x000000010020e5fe in llvm::ARMInstPrinter::printSOImmOperand (this=0x1020107e0, MI=0x7fff5fbfee70, OpNum=1, O=@0x1010bdf80) at ARMInstPrinter.cpp:254
#5 0x00000001001ffbc0 in llvm::ARMInstPrinter::printInstruction (this=0x1020107e0, MI=0x7fff5fbfee70, O=@0x1010bdf80) at ARMGenAsmWriter.inc:3236
#6 0x000000010020c27c in llvm::ARMInstPrinter::printInst (this=0x1020107e0, MI=0x7fff5fbfee70, O=@0x1010bdf80) at ARMInstPrinter.cpp:182
#7 0x000000010003cbff in PrintInsts (DisAsm=@0x10200f4e0, Printer=@0x1020107e0, Bytes=@0x7fff5fbff060, SM=@0x7fff5fbff078) at Disassembler.cpp:65
#8 0x000000010003c8b4 in llvm::Disassembler::disassemble (T=@0x1010c13c0, Triple=@0x1010b6798, Buffer=@0x102010690) at Disassembler.cpp:153
#9 0x000000010004095c in DisassembleInput (ProgName=0x7fff5fbff3f0 "/Volumes/data/llvm/git/trunk/Debug/bin/llvm-mc") at llvm-mc.cpp:347
#10 0x000000010003eefb in main (argc=4, argv=0x7fff5fbff298) at llvm-mc.cpp:374
(gdb) q
The program is running. Exit anyway? (y or n) y
[13:36:26] johnny:/Volumes/data/llvm/git/trunk (local-trunk) $
llvm-svn: 101053
the loop exit test. This usually doesn't come up for a variety of
reasons, but it isn't impossible, so make IndVarSimplify handle it
conservatively.
llvm-svn: 101008
variables. For example, with code like this:
for (i=0;i<n;++i)
if (i<n)
x[i] = 0;
IndVarSimplify will now recognize that i is always less than n inside
the loop, and eliminate the if.
llvm-svn: 101000
into adjacent loops. Also, ensure that the insert position is
dominated by the loop latch of any loop in the post-inc set which
has a latch.
llvm-svn: 100906
