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target/sparc: Rewrite gen_edge

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Drop the tables and compute the left and right edges directly.

Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
This commit is contained in:
Richard Henderson 2024-05-24 21:26:24 -07:00
parent fa9079a86d
commit 43db583802
1 changed files with 37 additions and 61 deletions
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98
target/sparc/translate.c
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@ -3519,11 +3519,10 @@ static bool trans_SDIVX(DisasContext *dc, arg_r_r_ri *a)
}
static bool gen_edge(DisasContext *dc, arg_r_r_r *a,
int width, bool cc, bool left)
int width, bool cc, bool little_endian)
{
TCGv dst, s1, s2, lo1, lo2;
uint64_t amask, tabl, tabr;
int shift, imask, omask;
TCGv dst, s1, s2, l, r, t, m;
uint64_t amask = address_mask_i(dc, -8);
dst = gen_dest_gpr(dc, a->rd);
s1 = gen_load_gpr(dc, a->rs1);
@ -3533,75 +3532,52 @@ static bool gen_edge(DisasContext *dc, arg_r_r_r *a,
gen_op_subcc(cpu_cc_N, s1, s2);
}
/*
* Theory of operation: there are two tables, left and right (not to
* be confused with the left and right versions of the opcode). These
* are indexed by the low 3 bits of the inputs. To make things "easy",
* these tables are loaded into two constants, TABL and TABR below.
* The operation index = (input & imask) << shift calculates the index
* into the constant, while val = (table >> index) & omask calculates
* the value we're looking for.
*/
l = tcg_temp_new();
r = tcg_temp_new();
t = tcg_temp_new();
switch (width) {
case 8:
imask = 0x7;
shift = 3;
omask = 0xff;
if (left) {
tabl = 0x80c0e0f0f8fcfeffULL;
tabr = 0xff7f3f1f0f070301ULL;
} else {
tabl = 0x0103070f1f3f7fffULL;
tabr = 0xfffefcf8f0e0c080ULL;
}
tcg_gen_andi_tl(l, s1, 7);
tcg_gen_andi_tl(r, s2, 7);
tcg_gen_xori_tl(r, r, 7);
m = tcg_constant_tl(0xff);
break;
case 16:
imask = 0x6;
shift = 1;
omask = 0xf;
if (left) {
tabl = 0x8cef;
tabr = 0xf731;
} else {
tabl = 0x137f;
tabr = 0xfec8;
}
tcg_gen_extract_tl(l, s1, 1, 2);
tcg_gen_extract_tl(r, s2, 1, 2);
tcg_gen_xori_tl(r, r, 3);
m = tcg_constant_tl(0xf);
break;
case 32:
imask = 0x4;
shift = 0;
omask = 0x3;
if (left) {
tabl = (2 << 2) | 3;
tabr = (3 << 2) | 1;
} else {
tabl = (1 << 2) | 3;
tabr = (3 << 2) | 2;
}
tcg_gen_extract_tl(l, s1, 2, 1);
tcg_gen_extract_tl(r, s2, 2, 1);
tcg_gen_xori_tl(r, r, 1);
m = tcg_constant_tl(0x3);
break;
default:
abort();
}
lo1 = tcg_temp_new();
lo2 = tcg_temp_new();
tcg_gen_andi_tl(lo1, s1, imask);
tcg_gen_andi_tl(lo2, s2, imask);
tcg_gen_shli_tl(lo1, lo1, shift);
tcg_gen_shli_tl(lo2, lo2, shift);
/* Compute Left Edge */
if (little_endian) {
tcg_gen_shl_tl(l, m, l);
tcg_gen_and_tl(l, l, m);
} else {
tcg_gen_shr_tl(l, m, l);
}
/* Compute Right Edge */
if (little_endian) {
tcg_gen_shr_tl(r, m, r);
} else {
tcg_gen_shl_tl(r, m, r);
tcg_gen_and_tl(r, r, m);
}
tcg_gen_shr_tl(lo1, tcg_constant_tl(tabl), lo1);
tcg_gen_shr_tl(lo2, tcg_constant_tl(tabr), lo2);
tcg_gen_andi_tl(lo1, lo1, omask);
tcg_gen_andi_tl(lo2, lo2, omask);
amask = address_mask_i(dc, -8);
tcg_gen_andi_tl(s1, s1, amask);
tcg_gen_andi_tl(s2, s2, amask);
/* Compute dst = (s1 == s2 ? lo1 : lo1 & lo2). */
tcg_gen_and_tl(lo2, lo2, lo1);
tcg_gen_movcond_tl(TCG_COND_EQ, dst, s1, s2, lo1, lo2);
/* Compute dst = (s1 == s2 under amask ? l : l & r) */
tcg_gen_xor_tl(t, s1, s2);
tcg_gen_and_tl(r, r, l);
tcg_gen_movcond_tl(TCG_COND_TSTEQ, dst, t, tcg_constant_tl(amask), r, l);
gen_store_gpr(dc, a->rd, dst);
return advance_pc(dc);