// Floating-point immediates on the SSE scalar paths: the constant is
// rewritten into a read from a read-only pool symbol ($f64.<hex> or
// $f32.<hex>, the IEEE-754 bits in the name), RIP-relative with the
// displacement left to the relocation.  A positive zero on the moves
// collapses to XORPS dst, dst; a negative zero keeps its sign bit and
// takes the pool.  The parenthesised $(-1.0) spelling is the one
// math/floor_amd64.s uses.  Every result is folded back so no
// instruction is dead.

#include "textflag.h"

// func floatimm(x float64) float64
TEXT ·floatimm(SB), NOSPLIT, $0-16
	MOVQ  x+0(FP), AX
	MOVQ  AX, X0
	// The floor kernel's sign fold: the parenthesised negative spelling.
	MOVSD $ (-1.0), X2
	ANDPD X2, X0
	// Positive and fractional constants on the scalar moves.
	MOVSD $1.5, X3
	MOVSD $0.5, X4
	MOVSS $2.5, X5
	MOVSS $-0.5, X6
	// A positive zero collapses to XORPS; a negative zero does not.
	MOVSD $0.0, X7
	MOVSS $0.0, X8
	MOVSD $-0.0, X9
	// The scalar arithmetic reads the pool through r/m (hypot's shape).
	ADDSD $1.0, X3
	SUBSD $0.5, X4
	MULSD $-2.5, X4
	DIVSD $2.0, X3
	ADDSS $0.25, X5
	// Fold everything into one double.
	ADDSD X5, X3
	ADDSD X6, X3
	ADDSD X7, X3
	ADDSD X8, X3
	ADDSD X9, X3
	ADDSD X4, X3
	ADDSD X0, X3
	MOVSD X3, ret+8(FP)
	RET

// func floatimmfloat32() float32
TEXT ·floatimmfloat32(SB), NOSPLIT, $0-4
	// The single-width pool constants ride the F3 prefix.
	MOVSS $1.0, X0
	MOVSS $-1.0, X1
	MOVSS $0.0, X2
	ADDSS $0.5, X0
	ADDSS X1, X0
	ADDSS X2, X0
	MOVSS X0, ret+0(FP)
	RET