diff options
Diffstat (limited to 'packages/gcc/7.5.0/0032-riscv-Make-__divdi3-handle-div-by-zero-same-as-hard.patch')
| -rw-r--r-- | packages/gcc/7.5.0/0032-riscv-Make-__divdi3-handle-div-by-zero-same-as-hard.patch | 40 |
1 files changed, 40 insertions, 0 deletions
diff --git a/packages/gcc/7.5.0/0032-riscv-Make-__divdi3-handle-div-by-zero-same-as-hard.patch b/packages/gcc/7.5.0/0032-riscv-Make-__divdi3-handle-div-by-zero-same-as-hard.patch new file mode 100644 index 00000000..47c25104 --- /dev/null +++ b/packages/gcc/7.5.0/0032-riscv-Make-__divdi3-handle-div-by-zero-same-as-hard.patch @@ -0,0 +1,40 @@ +From 4013baf99c38f7bca06a51f8301e8fb195ccfa33 Mon Sep 17 00:00:00 2001 +From: Jim Wilson <jimw@sifive.com> +Date: Tue, 2 Jun 2020 11:19:39 -0700 +Subject: [PATCH] RISC-V: Make __divdi3 handle div by zero same as hardware. + +The ISA manual specifies that divide by zero always returns -1 as the result. +We were failing to do that when the dividend was negative. + +Original patch from Virginie Moser. + + libgcc/ + * config/riscv/div.S (__divdi3): For negative arguments, change bgez + to bgtz. +--- + libgcc/config/riscv/div.S | 8 +++++--- + 1 file changed, 5 insertions(+), 3 deletions(-) + +diff --git a/libgcc/config/riscv/div.S b/libgcc/config/riscv/div.S +index 151f8e273a..17234324c1 100644 +--- a/libgcc/config/riscv/div.S ++++ b/libgcc/config/riscv/div.S +@@ -107,10 +107,12 @@ FUNC_END (__umoddi3) + /* Handle negative arguments to __divdi3. */ + .L10: + neg a0, a0 +- bgez a1, .L12 /* Compute __udivdi3(-a0, a1), then negate the result. */ ++ /* Zero is handled as a negative so that the result will not be inverted. */ ++ bgtz a1, .L12 /* Compute __udivdi3(-a0, a1), then negate the result. */ ++ + neg a1, a1 +- j __udivdi3 /* Compute __udivdi3(-a0, -a1). */ +-.L11: /* Compute __udivdi3(a0, -a1), then negate the result. */ ++ j __udivdi3 /* Compute __udivdi3(-a0, -a1). */ ++.L11: /* Compute __udivdi3(a0, -a1), then negate the result. */ + neg a1, a1 + .L12: + move t0, ra +-- +2.49.0 + |