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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.
This commit is contained in:
Jim Wilson 2020-06-02 11:19:39 -07:00
parent 578c013aa6
commit 4013baf99c
1 changed files with 5 additions and 3 deletions
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4
libgcc/config/riscv/div.S
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@ -107,7 +107,9 @@ 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. */