This is the mail archive of the
gcc-patches@gcc.gnu.org
mailing list for the GCC project.
[PATCH v2 2/5] or1k: Fix issues with msoft-div
- From: Stafford Horne <shorne at gmail dot com>
- To: GCC patches <gcc-patches at gcc dot gnu dot org>
- Cc: Openrisc <openrisc at lists dot librecores dot org>, Bernhard Reutner-Fischer <rep dot dot dot nop at gmail dot com>, Jeff Law <law at redhat dot com>, Stafford Horne <shorne at gmail dot com>
- Date: Wed, 3 Jul 2019 12:33:48 +0900
- Subject: [PATCH v2 2/5] or1k: Fix issues with msoft-div
- References: <20190703033351.11924-1-shorne@gmail.com>
Fixes bad assembly logic with software divide as reported by Richard Selvaggi.
Also, add a basic test to verify the soft math works when enabled.
gcc/testsuite/ChangeLog:
PR target/90362
* gcc.target/or1k/div-mul-3.c: New test.
libgcc/ChangeLog:
PR target/90362
* config/or1k/lib1funcs.S (__udivsi3): Change l.sfeqi
to l.sfeq and l.sfltsi to l.sflts equivalents as the immediate
instructions are not available on every processor. Change a
l.bnf to l.bf to fix logic issue.
---
Changes since v1:
- none
gcc/testsuite/gcc.target/or1k/div-mul-3.c | 31 +++++++++++++++++++++++
libgcc/config/or1k/lib1funcs.S | 6 ++---
2 files changed, 34 insertions(+), 3 deletions(-)
create mode 100644 gcc/testsuite/gcc.target/or1k/div-mul-3.c
diff --git a/gcc/testsuite/gcc.target/or1k/div-mul-3.c b/gcc/testsuite/gcc.target/or1k/div-mul-3.c
new file mode 100644
index 00000000000..2c4f91b7e98
--- /dev/null
+++ b/gcc/testsuite/gcc.target/or1k/div-mul-3.c
@@ -0,0 +1,31 @@
+/* { dg-do run } */
+/* { dg-options "-O2 -msoft-div -msoft-mul" } */
+
+struct testcase {
+ int a;
+ int b;
+ int c;
+ int expected;
+};
+
+struct testcase tests[] = {
+ {2, 200, 3, 133},
+ {3, 300, 3, 300},
+ {2, 500, 3, 333},
+ {4, 250, 3, 333},
+ {0, 0, 0, 0}
+};
+
+int calc (int a, int b, int c) {
+ return a * b / c;
+}
+
+int main () {
+ int fail = 0;
+ struct testcase *tc;
+
+ for (int i = 0; (tc = &tests[i], tc->c); i++)
+ fail |= (calc (tc->a, tc->b, tc->c) != tc->expected);
+
+ return fail;
+}
diff --git a/libgcc/config/or1k/lib1funcs.S b/libgcc/config/or1k/lib1funcs.S
index d2103923486..6d058977229 100644
--- a/libgcc/config/or1k/lib1funcs.S
+++ b/libgcc/config/or1k/lib1funcs.S
@@ -68,18 +68,18 @@ __udivmodsi3_internal:
is not clobbered by this routine, and use that as to
save a return address without creating a stack frame. */
- l.sfeqi r4, 0 /* division by zero; return 0. */
+ l.sfeq r4, r0 /* division by zero; return 0. */
l.ori r11, r0, 0 /* initial quotient */
l.bf 9f
l.ori r12, r3, 0 /* initial remainder */
/* Given X/Y, shift Y left until Y >= X. */
l.ori r6, r0, 1 /* mask = 1 */
-1: l.sfltsi r4, 0 /* y has msb set */
+1: l.sflts r4, r0 /* y has msb set */
l.bf 2f
l.sfltu r4, r12 /* y < x */
l.add r4, r4, r4 /* y <<= 1 */
- l.bnf 1b
+ l.bf 1b
l.add r6, r6, r6 /* mask <<= 1 */
/* Shift Y back to the right again, subtracting from X. */
--
2.21.0