mirror of
https://github.com/c64scene-ar/llvm-6502.git
synced 2024-08-20 11:29:24 +00:00
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@1911 91177308-0d34-0410-b5e6-96231b3b80d8
137 lines
4.0 KiB
LLVM
137 lines
4.0 KiB
LLVM
%AConst = constant int 123
|
|
|
|
implementation
|
|
|
|
; A SetCC whose result is used should produce instructions to
|
|
; compute the boolean value in a register. One whose result
|
|
; is unused will only generate the condition code but not
|
|
; the boolean result.
|
|
;
|
|
void "unusedBool"(int * %x, int * %y)
|
|
begin
|
|
; <label>:0 ; [#uses=0]
|
|
seteq int * %x, %y ; <bool>:0 [#uses=1]
|
|
not bool %0 ; <bool>:1 [#uses=0]
|
|
setne int * %x, %y ; <bool>:2 [#uses=0]
|
|
ret void
|
|
end
|
|
|
|
; A constant argument to a Phi produces a Cast instruction in the
|
|
; corresponding predecessor basic block. This checks a few things:
|
|
; -- phi arguments coming from the bottom of the same basic block
|
|
; (they should not be forward substituted in the machine code!)
|
|
; -- code generation for casts of various types
|
|
; -- use of immediate fields for integral constants of different sizes
|
|
; -- branch on a constant condition
|
|
;
|
|
void "mergeConstants"(int * %x, int * %y)
|
|
begin
|
|
; <label>:0
|
|
br label %Top
|
|
Top:
|
|
phi int [ 0, %0 ], [ 1, %Top ], [ 524288, %Next ]
|
|
phi float [ 0.0, %0 ], [ 1.0, %Top ], [ 2.0, %Next ]
|
|
phi double [ 0.5, %0 ], [ 1.5, %Top ], [ 2.5, %Next ]
|
|
phi bool [ true, %0 ], [ false,%Top ], [ true, %Next ]
|
|
br bool true, label %Top, label %Next
|
|
Next:
|
|
br label %Top
|
|
end
|
|
|
|
|
|
|
|
; A constant argument to a cast used only once should be forward substituted
|
|
; and loaded where needed, which happens is:
|
|
; -- User of cast has no immediate field
|
|
; -- User of cast has immediate field but constant is too large to fit
|
|
; or constant is not resolved until later (e.g., global address)
|
|
; -- User of cast uses it as a call arg. or return value so it is an implicit
|
|
; use but has to be loaded into a virtual register so that the reg.
|
|
; allocator can allocate the appropriate phys. reg. for it
|
|
;
|
|
int* "castconst"(float)
|
|
begin
|
|
; <label>:0
|
|
%castbig = cast ulong 99999999 to int
|
|
%castsmall = cast ulong 1 to int
|
|
%usebig = add int %castbig, %castsmall
|
|
|
|
%castglob = cast int* %AConst to long*
|
|
%dummyl = load long* %castglob
|
|
|
|
%castnull = cast ulong 0 to int*
|
|
ret int* %castnull
|
|
end
|
|
|
|
|
|
|
|
; Test branch-on-comparison-with-zero, in two ways:
|
|
; 1. can be folded
|
|
; 2. cannot be folded because result of comparison is used twice
|
|
;
|
|
void "testbool"(int, int) ; Def %0, %1
|
|
const int 0 ; Def 2
|
|
const int -4 ; Def 3
|
|
begin
|
|
; <label>:0
|
|
br label %Top
|
|
Top:
|
|
add int %0, %1 ; Def 4
|
|
sub int %4, %3 ; Def 5
|
|
setle int %5, %2 ; Def 0 - bool plane
|
|
br bool %0, label %retlbl, label %loop
|
|
|
|
loop:
|
|
add int %0, %1 ; Def 6
|
|
sub int %4, %3 ; Def 7
|
|
setle int %7, %2 ; Def 1 - bool
|
|
not bool %1 ; Def 2 - bool. first use of bool %1
|
|
br bool %1, label %loop, label %Top ; second use of bool %1
|
|
|
|
retlbl:
|
|
ret void
|
|
end
|
|
|
|
|
|
; Test branch on floating point comparison
|
|
;
|
|
void "testfloatbool"(float %x, float %y) ; Def %0, %1 - float
|
|
begin
|
|
; <label>:0
|
|
br label %Top
|
|
Top:
|
|
%p = add float %x, %y ; Def 2 - float
|
|
%z = sub float %x, %y ; Def 3 - float
|
|
%b = setle float %p, %z ; Def 0 - bool
|
|
%c = not bool %b ; Def 1 - bool
|
|
br bool %b, label %Top, label %goon
|
|
goon:
|
|
ret void
|
|
end
|
|
|
|
|
|
; Test cases where an LLVM instruction requires no machine
|
|
; instructions (e.g., cast int* to long). But there are 2 cases:
|
|
; 1. If the result register has only a single use and the use is in the
|
|
; same basic block, the operand will be copy-propagated during
|
|
; instruction selection.
|
|
; 2. If the result register has multiple uses or is in a different
|
|
; basic block, it cannot (or will not) be copy propagated during
|
|
; instruction selection. It will generate a
|
|
; copy instruction (add-with-0), but this copy should get coalesced
|
|
; away by the register allocator.
|
|
;
|
|
int "checkForward"(int %N, int* %A)
|
|
begin
|
|
|
|
bb2: ;;<label>
|
|
%reg114 = shl int %N, ubyte 2 ;;
|
|
%cast115 = cast int %reg114 to int* ;; reg114 will be propagated
|
|
%reg116 = add int* %A, %cast115 ;;
|
|
%reg118 = load int* %reg116 ;;
|
|
%cast117 = cast int %reg118 to long ;; reg118 will be copied 'cos
|
|
%reg159 = add long 1234567, %cast117 ;; cast117 has 2 uses, here
|
|
%reg160 = add long 7654321, %cast117 ;; and here.
|
|
ret void
|
|
end
|