1. Fold [mem] += (1|-1) into inc [mem]/dec [mem] to save some icache space.
2. Do not let token factor nodes prevent forming '[mem] op= val' folds.
llvm-svn: 19643
* Remove custom promotion for bool and byte select ops. Legalize now
promotes them for us.
* Allow folding ConstantPoolIndexes into EXTLOAD's, useful for float immediates.
* Declare which operations are not supported better.
* Add some hacky code for TRUNCSTORE to pretend that we have truncstore
for i16 types. This is useful for testing promotion code because I can
just remove 16-bit registers all together and verify that programs work.
llvm-svn: 19614
256.bzip2 from 7142 to 7103 lines of .s file.
Second, add initial support for folding loads into compares, though this code
is dynamically dead for now. :(
llvm-svn: 19493
Select [mem] += Val operations. For constants, we used to get:
mov %ECX, -32768
add %ECX, DWORD PTR [l4_match_start]
mov DWORD PTR [l4_match_start], %ECX
Now we get:
add DWORD PTR [l4_match_start], -32768
For other values we used to get:
mov %EBP, %EDI ;; because the add destroys the value
add %EBP, DWORD PTR [l4_input_len]
mov DWORD PTR [l4_input_len], %EBP
now we get:
add DWORD PTR [l4_input_len], %EDI
Both of these use less registers than the alternative, are faster and smaller.
llvm-svn: 19488
mov %ECX, %EAX
add %ECX, 32768
mov %SI, WORD PTR [2*%ECX + l13_prev]
Generate this:
mov %SI, WORD PTR [2*%ECX + l13_prev + 65536]
This occurs when you have a GEP instruction where an index is
"something + imm".
llvm-svn: 19472
int -> FP casting code. Note that we don't have to set it for FP operations
that take FP values as operands: whatever produces the FP value will set the
flag.
llvm-svn: 19451
evaluate the LHS or the RHS of an operation first. This causes good things
to happen. For example, instead of compiling a loop to this:
.LBBstrength_result7_1: # loopentry
movl 16(%esp), %edi
movl (%edi), %edi ;;; LOAD
movl (%ecx), %ebx
movl $2, (%eax,%ebx,4)
movl (%edx), %ebx
movl %esi, %ebp
addl $21, %ebp
addl $42, %esi
cmpl $0, %edi ;;; USE
cmovne %esi, %ebp
cmpl %ebp, %ebx
movl %ebp, %esi
jg .LBBstrength_result7_1
We now compile it to this:
.LBBstrength_result7_1: # loopentry
movl %edi, %ebx
addl $42, %ebx
addl $21, %edi
movl (%ecx), %ebp ;; LOAD
cmpl $0, %ebp ;; USE
cmovne %ebx, %edi
movl (%edx), %ebx
movl $2, (%eax,%ebx,4)
movl (%esi), %ebx
cmpl %edi, %ebx
jg .LBBstrength_result7_1
Which reduces register pressure enough (in this case) to avoid spilling in the
loop.
As another example, consider the CodeGen/X86/regpressure.ll testcase. We
used to generate this code for both cases:
regpressure1:
subl $32, %esp
movl %esi, 12(%esp)
movl %edi, 8(%esp)
movl %ebx, 4(%esp)
movl %ebp, (%esp)
movl 36(%esp), %ecx
movl (%ecx), %eax
movl 4(%ecx), %edx
movl %edx, 24(%esp)
movl 8(%ecx), %edx
movl %edx, 16(%esp)
movl 12(%ecx), %edx
movl 16(%ecx), %esi
movl 20(%ecx), %edi
movl 24(%ecx), %ebx
movl %ebx, 28(%esp)
movl 28(%ecx), %ebx
movl 32(%ecx), %ebp
movl %ebp, 20(%esp)
movl 36(%ecx), %ecx
imull 24(%esp), %eax
imull 16(%esp), %eax
imull %edx, %eax
imull %esi, %eax
imull %edi, %eax
imull 28(%esp), %eax
imull %ebx, %eax
imull 20(%esp), %eax
imull %ecx, %eax
movl (%esp), %ebp
movl 4(%esp), %ebx
movl 8(%esp), %edi
movl 12(%esp), %esi
addl $32, %esp
ret
This code is basically trying to do all of the loads first, then execute all
of the multiplies. Because we run out of registers, lots of spill code happens.
We now generate this code for both cases:
regpressure1:
movl 4(%esp), %ecx
movl (%ecx), %eax
movl 4(%ecx), %edx
imull %edx, %eax
movl 8(%ecx), %edx
imull %edx, %eax
movl 12(%ecx), %edx
imull %edx, %eax
movl 16(%ecx), %edx
imull %edx, %eax
movl 20(%ecx), %edx
imull %edx, %eax
movl 24(%ecx), %edx
imull %edx, %eax
movl 28(%ecx), %edx
imull %edx, %eax
movl 32(%ecx), %edx
imull %edx, %eax
movl 36(%ecx), %ecx
imull %ecx, %eax
ret
which is much nicer (when we fold loads into the muls it will be even better).
The old instruction selector used to produce the good code for regpressure1
but not for regpressure2, as it depended on the order of operations in the
LLVM code.
llvm-svn: 19449
of an ADDri (due to current restrictions on MachineOperand :( ). This allows
us to generate:
leal Data+16000, %edx
instead of:
movl $Data, %edx
addl $16000, %edx
llvm-svn: 19420
store float 123.45, float* %P
as an integer store. This adds handling of float immediate stores as integers
for arguments passed function calls.
This is now tested by CodeGen/X86/store-fp-constant.ll
llvm-svn: 19364
For now, this is the default, as the current selector is missing some big pieces.
To enable the new selector, pass -disable-pattern-isel=false to llc or lli.
llvm-svn: 19335
precisely represented as a float, put it into the constant pool as a
float.
2. Use the cbw/cwd/cdq instructions instead of an explicit SAR for signed
division.
llvm-svn: 19291
1. Add new instructions for checking parity flags: JP, JNP, SETP, SETNP.
2. Set the isCommutable and isPromotableTo3Address bits on several
instructions.
llvm-svn: 19246
don't support long double anyway, and this gives us FP results closer to
other targets.
This also speeds up 179.art from 41.4s to 18.32s, by eliminating a problem
with extra precision that causes an FP == comparison to fail (leading to
extra loop iterations).
llvm-svn: 18895
to Brian and the Sun compiler for pointing out that the obvious works :)
This also enables folding all long comparisons into setcc and branch
instructions: before we could only do == and !=
For example, for:
void test(unsigned long long A, unsigned long long B) {
if (A < B) foo();
}
We now generate:
test:
subl $4, %esp
movl %esi, (%esp)
movl 8(%esp), %eax
movl 12(%esp), %ecx
movl 16(%esp), %edx
movl 20(%esp), %esi
subl %edx, %eax
sbbl %esi, %ecx
jae .LBBtest_2 # UnifiedReturnBlock
.LBBtest_1: # then
call foo
movl (%esp), %esi
addl $4, %esp
ret
.LBBtest_2: # UnifiedReturnBlock
movl (%esp), %esi
addl $4, %esp
ret
Instead of:
test:
subl $12, %esp
movl %esi, 8(%esp)
movl %ebx, 4(%esp)
movl 16(%esp), %eax
movl 20(%esp), %ecx
movl 24(%esp), %edx
movl 28(%esp), %esi
cmpl %edx, %eax
setb %al
cmpl %esi, %ecx
setb %bl
cmove %ax, %bx
testb %bl, %bl
je .LBBtest_2 # UnifiedReturnBlock
.LBBtest_1: # then
call foo
movl 4(%esp), %ebx
movl 8(%esp), %esi
addl $12, %esp
ret
.LBBtest_2: # UnifiedReturnBlock
movl 4(%esp), %ebx
movl 8(%esp), %esi
addl $12, %esp
ret
llvm-svn: 18330
