is movccsi a standard names?

is movccsi a standard names?

[Shen Hui]

gcc，hello！
      i want to know the real defination of standard names (RTL),
and if movccsi is a stantard name (see gcc-2.95.3 arm.md),then why cannot emit conditional move rtl in generation.

for example (t.c):

	int foo(int a)
	{
		int b;
		if (a>0)
			b=1;
		else
			b=2;
		return b;
	}

arm-linux-gcc t.c -O -S -dr
its t.c.rtl as:

(note 8 6 10 0 NOTE_INSN_BLOCK_BEG)

(insn 10 8 11 (set (reg:CC 24 cc)
        (compare:CC (reg/v:SI 32)
            (const_int 0 [0x0]))) -1 (nil)
    (nil))

(jump_insn 11 10 14 (set (pc)
        (if_then_else (le (reg:CC 24 cc)
                (const_int 0 [0x0]))
            (label_ref 17)
            (pc))) 247 {*condbranch} (nil)
    (nil))

(insn 14 11 15 (set (reg/v:SI 33)
        (const_int 1 [0x1])) -1 (nil)
    (nil))

(jump_insn 15 14 16 (set (pc)
        (label_ref 21)) -1 (nil)
    (nil))

(barrier 16 15 17)

(code_label 17 16 20 3 "" [num uses: 0])

(insn 20 17 21 (set (reg/v:SI 33)
        (const_int 2 [0x2])) -1 (nil)
    (nil))

(code_label 21 20 24 4 "" [num uses: 0])

(insn 24 21 25 (set (reg/i:SI 0 r0)
        (reg/v:SI 33)) -1 (nil)
    (nil))

(insn 25 24 26 (use (reg/i:SI 0 r0)) -1 (nil)
    (nil))

(jump_insn 26 25 27 (set (pc)
        (label_ref 32)) -1 (nil)
    (nil))

(barrier 27 26 29)

(note 29 27 30 0 NOTE_INSN_BLOCK_END)

can anybody help me ?
　　

 				
　　　　　　　　　　　　　　Shen Hui
　　　　　　　　　　　　　　shenhui@mprc.pku.edu.cn
　　　　　　　　　　　　　　　　　2003-08-05

Re: is movccsi a standard names?

[Jim Wilson]

Shen Hui wrote:
>       i want to know the real defination of standard names (RTL),
> and if movccsi is a stantard name (see gcc-2.95.3 arm.md),then why cannot emit conditional move rtl in generation.

movcc is for moving the condition code value from one place to another.
cmov is for generating condition moves.

The .rtl file is before any optimization pass, so it won't have any cmov
instructions.  They are only created by optimizations.

Using current gcc 3.x development sources, I get movlt/movgt
instructions for this example which is apparently what you want.

Jim

Re: is movccsi a standard names?

[Richard Earnshaw]

> Shen Hui wrote:
> >       i want to know the real defination of standard names (RTL),
> > and if movccsi is a stantard name (see gcc-2.95.3 arm.md),then why cannot emit conditional move rtl in generation.
> 
> movcc is for moving the condition code value from one place to another.
> cmov is for generating condition moves.

There's some confusion here.  ARM has movsicc (note the order of si and cc 
is reversed).  This is an instruction that matches mov<mode>cc in the rtl 
expanders.  In fact, these instructions are not used during initial 
expansion into RTL, but are generated at later stages of optimization.

R.