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Type:
Bug
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Resolution: Won't Fix
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Priority:
Not Prioritized
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Code Generation Tools
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CODEGEN-9045
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C2000_21.6.0.LTS
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default
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No indication there is a bug. Assembly will vary between optimized and unoptimized code, as with any code compiled with different option sets.
The attached file has these lines ...
struct bit_field_tag {
uint32_t u8 : 8;
uint32_t u24 : 24;
} global_bit_field;
uint32_t fxn() { return global_bit_field.u24; }
Build it ...
% cl2000 -s bf_bug.c
Inspect the resulting assembly to see these lines.
;----------------------------------------------------------------------
; 8 | uint32_t fxn() { return global_bit_field.u24; }
;----------------------------------------------------------------------
MOVW DP,#_global_bit_field ; [CPU_ARAU]
CLRC SXM ; [CPU_ALU]
MOVL ACC,@_global_bit_field ; [CPU_ALU] |8|
SFR ACC,8 ; [CPU_ALU] |8|
ANDB AH,#255 ; [CPU_ALU] |8|
The ANDB should not be present. For confirmation, build the same code with optimization ...
% cl2000 -s -o bf_bug.c
This generates ...
;*** 8 ----------------------- return *&global_bit_field>>8;
MOVW DP,#_global_bit_field ; [CPU_ARAU]
CLRC SXM ; [CPU_ALU]
.dwpsn file "bf_bug.c",line 8,column 18,is_stmt,isa 0
MOVL ACC,@_global_bit_field ; [CPU_ALU] |8|
SFR ACC,8 ; [CPU_ALU] |8|
Note the ANDB is not present.
