9.20.3 M32R Warnings

There are several warning and error messages that can be produced by as which are specific to the M32R:

output of 1st instruction is the same as an input to 2nd instruction - is this intentional ?

This message is only produced if warnings for explicit parallel conflicts have been enabled. It indicates that the assembler has encountered a parallel instruction in which the destination register of the left hand instruction is used as an input register in the right hand instruction. For example in this code fragment ‘mv r1, r2 || neg r3, r1’ register r1 is the destination of the move instruction and the input to the neg instruction.

output of 2nd instruction is the same as an input to 1st instruction - is this intentional ?

This message is only produced if warnings for explicit parallel conflicts have been enabled. It indicates that the assembler has encountered a parallel instruction in which the destination register of the right hand instruction is used as an input register in the left hand instruction. For example in this code fragment ‘mv r1, r2 || neg r2, r3’ register r2 is the destination of the neg instruction and the input to the move instruction.

instruction ‘...’ is for the M32RX only

This message is produced when the assembler encounters an instruction which is only supported by the M32Rx processor, and the ‘-m32rx’ command-line flag has not been specified to allow assembly of such instructions.

unknown instruction ‘...’

This message is produced when the assembler encounters an instruction which it does not recognize.

only the NOP instruction can be issued in parallel on the m32r

This message is produced when the assembler encounters a parallel instruction which does not involve a NOP instruction and the ‘-m32rx’ command-line flag has not been specified. Only the M32Rx processor is able to execute two instructions in parallel.

instruction ‘...’ cannot be executed in parallel.

This message is produced when the assembler encounters a parallel instruction which is made up of one or two instructions which cannot be executed in parallel.

Instructions share the same execution pipeline

This message is produced when the assembler encounters a parallel instruction whose components both use the same execution pipeline.

Instructions write to the same destination register.

This message is produced when the assembler encounters a parallel instruction where both components attempt to modify the same register. For example these code fragments will produce this message: ‘mv r1, r2 || neg r1, r3’ ‘jl r0 || mv r14, r1’ ‘st r2, @-r1 || mv r1, r3’ ‘mv r1, r2 || ld r0, @r1+’ ‘cmp r1, r2 || addx r3, r4’ (Both write to the condition bit)