diff mbox series

[kvm-unit-tests,2/2] arm: add eabi version of 64-bit division functions

Message ID 20210511174106.703235-3-pbonzini@redhat.com (mailing list archive)
State New, archived
Headers show
Series fix long division routines for ARM eabi | expand

Commit Message

Paolo Bonzini May 11, 2021, 5:41 p.m. UTC
eabi prescribes different entry points for 64-bit division on
32-bit platforms.  Implement a wrapper for the GCC-style __divmoddi4
and __udivmoddi4 functions.

Reported-by: Alexandru Elisei <alexandru.elisei@arm.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 arm/Makefile.arm  |  1 +
 lib/arm/ldivmod.S | 32 ++++++++++++++++++++++++++++++++
 2 files changed, 33 insertions(+)
 create mode 100644 lib/arm/ldivmod.S
diff mbox series

Patch

diff --git a/arm/Makefile.arm b/arm/Makefile.arm
index 687a8ed..3a4cc6b 100644
--- a/arm/Makefile.arm
+++ b/arm/Makefile.arm
@@ -24,6 +24,7 @@  cflatobjs += lib/arm/spinlock.o
 cflatobjs += lib/arm/processor.o
 cflatobjs += lib/arm/stack.o
 cflatobjs += lib/ldiv32.o
+cflatobjs += lib/arm/ldivmod.o
 
 # arm specific tests
 tests =
diff --git a/lib/arm/ldivmod.S b/lib/arm/ldivmod.S
new file mode 100644
index 0000000..de11ac9
--- /dev/null
+++ b/lib/arm/ldivmod.S
@@ -0,0 +1,32 @@ 
+// EABI ldivmod and uldivmod implementation based on libcompiler-rt
+//
+// This file is dual licensed under the MIT and the University of Illinois Open
+// Source Licenses.
+
+	.syntax unified
+	.align 2
+	.globl __aeabi_uldivmod
+	.type __aeabi_uldivmod, %function
+__aeabi_uldivmod:
+	push	{r11, lr}
+	sub	sp, sp, #16
+	add	r12, sp, #8
+	str	r12, [sp]                // third argument to __udivmoddi4
+	bl	__udivmoddi4
+	ldr	r2, [sp, #8]             // remainder returned in r2-r3
+	ldr	r3, [sp, #12]
+	add	sp, sp, #16
+	pop	{r11, pc}
+
+	.globl __aeabi_ldivmod
+	.type __aeabi_ldivmod, %function
+__aeabi_ldivmod:
+	push	{r11, lr}
+	sub	sp, sp, #16
+	add	r12, sp, #8
+	str	r12, [sp]                // third argument to __divmoddi4
+	bl	__divmoddi4
+	ldr	r2, [sp, #8]             // remainder returned in r2-r3
+	ldr	r3, [sp, #12]
+	add	sp, sp, #16
+	pop	{r11, pc}