From 26478769a60424d54977e33febd81c0b8fb01828 Mon Sep 17 00:00:00 2001 From: Marcus Comstedt <marcus@mc.pp.se> Date: Tue, 23 Feb 2021 22:31:17 +0100 Subject: RISC-V: Fix optimized strcmp on big endian --- newlib/libc/machine/riscv/strcmp.S | 40 ++++++++++++++++++++++++++++++++++---- 1 file changed, 36 insertions(+), 4 deletions(-) (limited to 'newlib') diff --git a/newlib/libc/machine/riscv/strcmp.S b/newlib/libc/machine/riscv/strcmp.S index eaf6d4b..9af9ca1 100644 --- a/newlib/libc/machine/riscv/strcmp.S +++ b/newlib/libc/machine/riscv/strcmp.S @@ -11,10 +11,6 @@ #include <sys/asm.h> -#if BYTE_ORDER != LITTLE_ENDIAN -# error -#endif - .text .globl strcmp .type strcmp, @function @@ -96,6 +92,9 @@ strcmp: .Lmismatch: # words don't match, but a2 has no null byte. + +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ + #if __riscv_xlen == 64 sll a4, a2, 48 sll a5, a3, 48 @@ -128,6 +127,39 @@ strcmp: sub a0, a4, a5 ret +#else + +#if __riscv_xlen == 64 + srl a4, a2, 48 + srl a5, a3, 48 + bne a4, a5, .Lmismatch_lower + srl a4, a2, 32 + srl a5, a3, 32 + bne a4, a5, .Lmismatch_lower +#endif + srl a4, a2, 16 + srl a5, a3, 16 + bne a4, a5, .Lmismatch_lower + + srl a4, a2, 8 + srl a5, a3, 8 + bne a4, a5, 1f + and a4, a2, 0xff + and a5, a3, 0xff +1:sub a0, a4, a5 + ret + +.Lmismatch_lower: + srl a2, a4, 8 + srl a3, a5, 8 + bne a2, a3, 1f + and a2, a4, 0xff + and a3, a5, 0xff +1:sub a0, a2, a3 + ret + +#endif + .Lmisaligned: # misaligned lbu a2, 0(a0) -- cgit v1.1