converted __*shift to __*shift_nz when applicable

Author: ZERICO2005

src/crt/dtof.src

@@ -32,7 +32,7 @@ __dtof_helper:
 	push	de
 	pop	bc
 	ld	l, 5
-	call	__lshru
+	call	__lshru_nz
 	push	bc
 	pop	hl
 .L.finish_inf_nan:
@@ -101,7 +101,8 @@ __dtof:
 	and	a, $1F
 .L.round_up:
 .L.round_down:
-	call	__llshru
+	; BC:UDE:UHL >>= 29
+	call	__llshru_nz
 	; B, C, and UDE are zero here
 	or	a, a
 	jr	z, .L.no_round
@@ -192,7 +193,7 @@ __dtof:
 	and	a, $0F
 	or	a, $10
 
-	call	__lshru
+	call	__lshru_nz
 	xor	a, a	; subnormal exponent
 	; HL = BC >> 1
 	scf
@@ -216,5 +217,5 @@ __dtof:
 
 	.extern	__lland
 	.extern	__llcmpzero
-	.extern	__llshru
-	.extern	__lshru
+	.extern	__llshru_nz
+	.extern	__lshru_nz

src/crt/dtoll.src

@@ -50,7 +50,7 @@ __dtoull:
 	ld	l, a
 	ex	(sp), hl
 	; shift is non-zero and [1, 11] in the non-UB case
-	call	c, __llshl
+	call	c, __llshl_nz
 	jr	.finish
 .shift_right:
 	; A is [-1, -52]
@@ -85,5 +85,5 @@ __dtoull:
 	jr	.finish_zero_or_one
 
 	.extern	__llneg
-	.extern	__llshl
+	.extern	__llshl_nz
 	.extern	__llshru

src/crt/ftod.src

@@ -71,9 +71,9 @@ __ftod:
 .L.subnormal:
 	; since this is subnormal, the LSB of the exponent is already zero
 	call	__ictlz
-	ld	c, a
+	ld	c, a	; A is [1, 23]
 	; shift until the MSB of the mantissa is the LSB of the exponent
-	call	__ishl
+	call	__ishl_nz
 	; (Float64_bias - Float32_bias) = $0380
 	; expon = (Float64_bias - Float32_bias) - clz_result
 	add	hl, hl
@@ -101,4 +101,4 @@ __ftod:
 	jr	.L.shift_28
 
 	.extern	__ictlz
-	.extern	__ishl
+	.extern	__ishl_nz

src/crt/ltod.src

@@ -69,7 +69,7 @@ __lltod:
 	pop	bc
 
 	ex	(sp), hl	; (SP) = shift
-	call	__llshru
+	call	__llshru_nz
 	add	a, 51 - 1	; compensate for the implicit mantissa bit
 
 	; BC/exponent = [$434*, $43E*]
@@ -174,7 +174,7 @@ __ltod:
 	.extern	__lctlz
 	.extern	__llctlz
 	.extern	__llshl
-	.extern	__llshru
+	.extern	__llshru_nz
 	.extern	__llneg
 	.extern	__lladd_1
 	.extern	___fe_cur_env

src/libc/frexpf.src

@@ -54,10 +54,10 @@ _frexp:
 	add	hl, de
 	inc	hl	; restore HL
 	jr	nc, .L.ret_zero
-	; input: HL output: A
+	; input: HL output: A in [1, 23]
 	call	__ictlz
 	ld	c, a
-	call	__ishl
+	call	__ishl_nz
 	ld	(iy + 3), hl
 	sub	a, 131	; (127 + 3) + 1? idk where this magic number comes from
 	cpl
@@ -69,6 +69,6 @@ _frexp:
 	jr	.L.ret_subnormal
 
 	.extern	__ictlz
-	.extern	__ishl
+	.extern	__ishl_nz
 
 .endif

src/libc/truncf.src

@@ -31,7 +31,7 @@ _truncf:
 	neg
 	ld	d, c	; store C
 	ld	c, a
-	call	__ishl
+	call	__ishl_nz
 	ld	c, d	; restore C
 	jp	__iand
 
@@ -49,5 +49,5 @@ _truncf:
 	sbc	hl, hl
 	ret
 
-	.extern	__ishl
+	.extern	__ishl_nz
 	.extern	__iand