Fcmp, Instructions – Renesas M32R-FPU User Manual

Page 76

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3

3-38

M32R-FPU Software Manual (Rev.1.01)

INSTRUCTIONS

3.2 Instruction description

FCMP

FCMP

src1

1101

src2

0000

dest

0000

0000

1100

FCMP Rdest,Rsrc1,Rsrc2

[Mnemonic]

FCMP Rdest,Rsrc1,Rsrc2

[Function]

Floating-point compare

Rdest = (comparison results of Rsrc1 and Rsrc2);

When at least one value, either Rsrc1 or Rsrc2, is SNaN, a floating-point exception (other than

Invalid Operation Exception) occurs.

[Description]

Compare the floating-point single precision values stored in Rsrc1 and Rsrc2 and store the

result in Rdest. The results of the comparison can be determined y the following methods.

The DN bit of FPSR handles the conversion of denormalized numbers. The condition bit (C)

remains unchanged.

[EIT occurrence]

Floating-Point Exceptions (FPE)

• Unimplemented Operation Exception (UIPL)

• Invalid Operation Exception (IVLD)

[Encoding]

floating point Instructions

Floating-point compare

[M32R-FPU Extended Instruction]

Rdest

Comparison Results

Typical instructions used to

determine comparison results

b0=0

All bits, b1 to b31, are 0.

Rsrc1=Rsrc2

beqz Rdest, LABEL

bgtz Rdest, LABEL

bltz Rdest, LABEL

Rsrc1>Rsrc2

Rsrc1<Rsrc2

Comparison invalid

Bits b1 to b31 are an undefined.

All others

b1 to b9=111 1111 11,

Bits b10 to b31 are an undefined.

b0=1

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