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Diffstat (limited to 'arch/xtensa/lib/umulsidi3.S')
| -rw-r--r-- | arch/xtensa/lib/umulsidi3.S | 233 |
1 files changed, 233 insertions, 0 deletions
diff --git a/arch/xtensa/lib/umulsidi3.S b/arch/xtensa/lib/umulsidi3.S new file mode 100644 index 000000000000..5da501b57813 --- /dev/null +++ b/arch/xtensa/lib/umulsidi3.S @@ -0,0 +1,233 @@ +/* SPDX-License-Identifier: GPL-2.0-or-later WITH GCC-exception-2.0 */ +#include <linux/linkage.h> +#include <asm/asmmacro.h> +#include <asm/core.h> + +#if XCHAL_HAVE_MUL16 || XCHAL_HAVE_MUL32 || XCHAL_HAVE_MAC16 +#define XCHAL_NO_MUL 0 +#else +#define XCHAL_NO_MUL 1 +#endif + +ENTRY(__umulsidi3) + +#ifdef __XTENSA_CALL0_ABI__ + abi_entry(32) + s32i a12, sp, 16 + s32i a13, sp, 20 + s32i a14, sp, 24 + s32i a15, sp, 28 +#elif XCHAL_NO_MUL + /* This is not really a leaf function; allocate enough stack space + to allow CALL12s to a helper function. */ + abi_entry(32) +#else + abi_entry_default +#endif + +#ifdef __XTENSA_EB__ +#define wh a2 +#define wl a3 +#else +#define wh a3 +#define wl a2 +#endif /* __XTENSA_EB__ */ + + /* This code is taken from the mulsf3 routine in ieee754-sf.S. + See more comments there. */ + +#if XCHAL_HAVE_MUL32_HIGH + mull a6, a2, a3 + muluh wh, a2, a3 + mov wl, a6 + +#else /* ! MUL32_HIGH */ + +#if defined(__XTENSA_CALL0_ABI__) && XCHAL_NO_MUL + /* a0 and a8 will be clobbered by calling the multiply function + but a8 is not used here and need not be saved. */ + s32i a0, sp, 0 +#endif + +#if XCHAL_HAVE_MUL16 || XCHAL_HAVE_MUL32 + +#define a2h a4 +#define a3h a5 + + /* Get the high halves of the inputs into registers. */ + srli a2h, a2, 16 + srli a3h, a3, 16 + +#define a2l a2 +#define a3l a3 + +#if XCHAL_HAVE_MUL32 && !XCHAL_HAVE_MUL16 + /* Clear the high halves of the inputs. This does not matter + for MUL16 because the high bits are ignored. */ + extui a2, a2, 0, 16 + extui a3, a3, 0, 16 +#endif +#endif /* MUL16 || MUL32 */ + + +#if XCHAL_HAVE_MUL16 + +#define do_mul(dst, xreg, xhalf, yreg, yhalf) \ + mul16u dst, xreg ## xhalf, yreg ## yhalf + +#elif XCHAL_HAVE_MUL32 + +#define do_mul(dst, xreg, xhalf, yreg, yhalf) \ + mull dst, xreg ## xhalf, yreg ## yhalf + +#elif XCHAL_HAVE_MAC16 + +/* The preprocessor insists on inserting a space when concatenating after + a period in the definition of do_mul below. These macros are a workaround + using underscores instead of periods when doing the concatenation. */ +#define umul_aa_ll umul.aa.ll +#define umul_aa_lh umul.aa.lh +#define umul_aa_hl umul.aa.hl +#define umul_aa_hh umul.aa.hh + +#define do_mul(dst, xreg, xhalf, yreg, yhalf) \ + umul_aa_ ## xhalf ## yhalf xreg, yreg; \ + rsr dst, ACCLO + +#else /* no multiply hardware */ + +#define set_arg_l(dst, src) \ + extui dst, src, 0, 16 +#define set_arg_h(dst, src) \ + srli dst, src, 16 + +#ifdef __XTENSA_CALL0_ABI__ +#define do_mul(dst, xreg, xhalf, yreg, yhalf) \ + set_arg_ ## xhalf (a13, xreg); \ + set_arg_ ## yhalf (a14, yreg); \ + call0 .Lmul_mulsi3; \ + mov dst, a12 +#else +#define do_mul(dst, xreg, xhalf, yreg, yhalf) \ + set_arg_ ## xhalf (a14, xreg); \ + set_arg_ ## yhalf (a15, yreg); \ + call12 .Lmul_mulsi3; \ + mov dst, a14 +#endif /* __XTENSA_CALL0_ABI__ */ + +#endif /* no multiply hardware */ + + /* Add pp1 and pp2 into a6 with carry-out in a9. */ + do_mul(a6, a2, l, a3, h) /* pp 1 */ + do_mul(a11, a2, h, a3, l) /* pp 2 */ + movi a9, 0 + add a6, a6, a11 + bgeu a6, a11, 1f + addi a9, a9, 1 +1: + /* Shift the high half of a9/a6 into position in a9. Note that + this value can be safely incremented without any carry-outs. */ + ssai 16 + src a9, a9, a6 + + /* Compute the low word into a6. */ + do_mul(a11, a2, l, a3, l) /* pp 0 */ + sll a6, a6 + add a6, a6, a11 + bgeu a6, a11, 1f + addi a9, a9, 1 +1: + /* Compute the high word into wh. */ + do_mul(wh, a2, h, a3, h) /* pp 3 */ + add wh, wh, a9 + mov wl, a6 + +#endif /* !MUL32_HIGH */ + +#if defined(__XTENSA_CALL0_ABI__) && XCHAL_NO_MUL + /* Restore the original return address. */ + l32i a0, sp, 0 +#endif +#ifdef __XTENSA_CALL0_ABI__ + l32i a12, sp, 16 + l32i a13, sp, 20 + l32i a14, sp, 24 + l32i a15, sp, 28 + abi_ret(32) +#else + abi_ret_default +#endif + +#if XCHAL_NO_MUL + + .macro do_addx2 dst, as, at, tmp +#if XCHAL_HAVE_ADDX + addx2 \dst, \as, \at +#else + slli \tmp, \as, 1 + add \dst, \tmp, \at +#endif + .endm + + .macro do_addx4 dst, as, at, tmp +#if XCHAL_HAVE_ADDX + addx4 \dst, \as, \at +#else + slli \tmp, \as, 2 + add \dst, \tmp, \at +#endif + .endm + + .macro do_addx8 dst, as, at, tmp +#if XCHAL_HAVE_ADDX + addx8 \dst, \as, \at +#else + slli \tmp, \as, 3 + add \dst, \tmp, \at +#endif + .endm + + /* For Xtensa processors with no multiply hardware, this simplified + version of _mulsi3 is used for multiplying 16-bit chunks of + the floating-point mantissas. When using CALL0, this function + uses a custom ABI: the inputs are passed in a13 and a14, the + result is returned in a12, and a8 and a15 are clobbered. */ + .align 4 +.Lmul_mulsi3: + abi_entry_default + + .macro mul_mulsi3_body dst, src1, src2, tmp1, tmp2 + movi \dst, 0 +1: add \tmp1, \src2, \dst + extui \tmp2, \src1, 0, 1 + movnez \dst, \tmp1, \tmp2 + + do_addx2 \tmp1, \src2, \dst, \tmp1 + extui \tmp2, \src1, 1, 1 + movnez \dst, \tmp1, \tmp2 + + do_addx4 \tmp1, \src2, \dst, \tmp1 + extui \tmp2, \src1, 2, 1 + movnez \dst, \tmp1, \tmp2 + + do_addx8 \tmp1, \src2, \dst, \tmp1 + extui \tmp2, \src1, 3, 1 + movnez \dst, \tmp1, \tmp2 + + srli \src1, \src1, 4 + slli \src2, \src2, 4 + bnez \src1, 1b + .endm + +#ifdef __XTENSA_CALL0_ABI__ + mul_mulsi3_body a12, a13, a14, a15, a8 +#else + /* The result will be written into a2, so save that argument in a4. */ + mov a4, a2 + mul_mulsi3_body a2, a4, a3, a5, a6 +#endif + abi_ret_default +#endif /* XCHAL_NO_MUL */ + +ENDPROC(__umulsidi3) +EXPORT_SYMBOL(__umulsidi3) |