M32R-Warnings - Using as
Description: Using as

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#### 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 whoes 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)