Module Name: src
Committed By: uwe
Date: Fri Aug 5 01:59:40 UTC 2011
Modified Files:
src/sys/lib/libkern/arch/sh3: sdivsi3.S udivsi3.S
Log Message:
Reword the comment about "millicode" nature of these functions and add
it to sdivsi3.S too.
Remove !_KERNEL code left over from the days when we shared these
files with userland.
Use .L prefix for local label.
To generate a diff of this commit:
cvs rdiff -u -r1.11 -r1.12 src/sys/lib/libkern/arch/sh3/sdivsi3.S
cvs rdiff -u -r1.10 -r1.11 src/sys/lib/libkern/arch/sh3/udivsi3.S
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/lib/libkern/arch/sh3/sdivsi3.S
diff -u src/sys/lib/libkern/arch/sh3/sdivsi3.S:1.11 src/sys/lib/libkern/arch/sh3/sdivsi3.S:1.12
--- src/sys/lib/libkern/arch/sh3/sdivsi3.S:1.11 Thu Jul 14 09:48:03 2011
+++ src/sys/lib/libkern/arch/sh3/sdivsi3.S Fri Aug 5 01:59:39 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: sdivsi3.S,v 1.11 2011/07/14 09:48:03 mrg Exp $ */
+/* $NetBSD: sdivsi3.S,v 1.12 2011/08/05 01:59:39 uwe Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
@@ -36,9 +36,26 @@
#include <machine/asm.h>
#if defined(LIBC_SCCS)
- RCSID("$NetBSD: sdivsi3.S,v 1.11 2011/07/14 09:48:03 mrg Exp $")
+ RCSID("$NetBSD: sdivsi3.S,v 1.12 2011/08/05 01:59:39 uwe Exp $")
#endif
+/*
+ * IMPOTANT: This function is special.
+ *
+ * This function is an auxiliary "millicode" function that is
+ * referenced by the code generated by gcc for signed integer
+ * division. But gcc does NOT treat a call to this function as an
+ * ordinary function call - it can clobber only R1, R2 and R3.
+ *
+ * See the definition of "divsi3_i1" in gcc/config/sh/sh.md
+ *
+ * As the consequence this function cannot be called via any
+ * indirection that assumes normal calling convention:
+ *
+ * . cannot have _PROF_PROLOGUE
+ * . cannot be called via PLT (not relevant for kernel)
+ */
+
#ifdef __ELF__
.hidden __sdivsi3
@@ -51,7 +68,7 @@
mov r5, r1
tst r1, r1
- bt div_by_zero
+ bt .L_div_by_zero
mov #0, r2
div0s r2, r0
@@ -70,33 +87,6 @@
rts
addc r2, r0
-div_by_zero:
-#ifdef _KERNEL
+.L_div_by_zero:
rts
mov #0, r0
-#else
- mov.l r14, @-r15
- sts.l pr, @-r15
- mov r15, r14
-
- mov.l L_raise, r1
-#ifdef PIC
-1: bsrf r1
-#else
- jsr @r1
-#endif
- mov #8, r4 /* delay slot. 8 <- SIGFPE. */
- mov #0, r0
-
- lds.l @r15+, pr
- rts
- mov.l @r15+, r14
-
- .align 2
-L_raise:
-#ifdef PIC
- .long _C_LABEL(raise)-(1b+4)
-#else
- .long _C_LABEL(raise)
-#endif
-#endif
Index: src/sys/lib/libkern/arch/sh3/udivsi3.S
diff -u src/sys/lib/libkern/arch/sh3/udivsi3.S:1.10 src/sys/lib/libkern/arch/sh3/udivsi3.S:1.11
--- src/sys/lib/libkern/arch/sh3/udivsi3.S:1.10 Thu Jul 14 09:48:04 2011
+++ src/sys/lib/libkern/arch/sh3/udivsi3.S Fri Aug 5 01:59:39 2011
@@ -1,4 +1,4 @@
-/* $NetBSD: udivsi3.S,v 1.10 2011/07/14 09:48:04 mrg Exp $ */
+/* $NetBSD: udivsi3.S,v 1.11 2011/08/05 01:59:39 uwe Exp $ */
/*-
* Copyright (c) 1990 The Regents of the University of California.
@@ -36,26 +36,24 @@
#include <machine/asm.h>
#if defined(LIBC_SCCS)
- RCSID("$NetBSD: udivsi3.S,v 1.10 2011/07/14 09:48:04 mrg Exp $")
+ RCSID("$NetBSD: udivsi3.S,v 1.11 2011/08/05 01:59:39 uwe Exp $")
#endif
/*
* IMPOTANT: This function is special.
*
- * This function is an auxiliary function that is referenced by the
- * code generated by gcc for integer division. But gcc does NOT treat
- * a call to this function as an ordinary function call w.r.t. the set
- * of register this call clobbers. See the definition of "udivsi3_i1"
- * in gcc/config/sh/sh.md.
- *
- * Any call to this function MUST NOT clobber any registers besides r4
- * and r0, where the result is returned. At the time of the call the
- * r4 contains the first argument, so we are only left with r0, and we
- * cannot do anything meaningful using only one register. The
- * consequences are:
+ * This function is an auxiliary "millicode" function that is
+ * referenced by the code generated by gcc for unsigned integer
+ * division. But gcc does NOT treat a call to this function as an
+ * ordinary function call - it can clobber only R4.
*
- * . this function cannot have _PROF_PROLOGUE
- * . this function cannot be called via PLT
+ * See the definition of "udivsi3_i1" in gcc/config/sh/sh.md
+ *
+ * As the consequence this function cannot be called via any
+ * indirection that assumes normal calling convention:
+ *
+ * . cannot have _PROF_PROLOGUE
+ * . cannot be called via PLT (not relevant for kernel)
*/
@@ -67,7 +65,7 @@
/* r0 <= r4 / r5 */
NENTRY(__udivsi3)
tst r5, r5
- bt div_by_zero
+ bt .L_div_by_zero
mov #0, r0
div0u
@@ -83,33 +81,6 @@
rts
mov r4, r0
-div_by_zero:
-#ifdef _KERNEL
+.L_div_by_zero:
rts
mov #0, r0
-#else
- mov.l r14, @-r15
- sts.l pr, @-r15
- mov r15, r14
-
- mov.l L_raise, r1
-#ifdef PIC
-1: bsrf r1
-#else
- jsr @r1
-#endif
- mov #8, r4 /* delay slot. 8 <- SIGFPE. */
- mov #0, r0
-
- lds.l @r15+, pr
- rts
- mov.l @r15+, r14
-
- .align 2
-L_raise:
-#ifdef PIC
- .long _C_LABEL(raise)-(1b+4)
-#else
- .long _C_LABEL(raise)
-#endif
-#endif
