target-ppc: Bug Fix: rlwnm

The rlwnm specification includes the ROTL32 operation, which is defined
to be a left rotation of two copies of the least significant 32 bits of
the source GPR.

The current implementation is incorrect on 64-bit implementations in that
it rotates a single copy of the least significant 32 bits, padding with
zeroes in the most significant bits.

Fix the code to properly implement this ROTL32 operation.

Example:

R3 = 0000000000000002
R4 = 7FFFFFFFFFFFFFFF
rlwnm 3,3,4,31,16
R3 expected : 0000000100000001
R3 actual   : 0000000000000001 (without this patch)

Signed-off-by: Tom Musta <tommusta@gmail.com>
Signed-off-by: Alexander Graf <agraf@suse.de>
This commit is contained in:
Tom Musta 2014-08-12 08:45:04 -05:00 committed by Alexander Graf
parent a7f23d0f8b
commit 1c0a150f4b

View File

@ -1698,7 +1698,7 @@ static void gen_rlwnm(DisasContext *ctx)
uint32_t mb, me;
TCGv t0;
#if defined(TARGET_PPC64)
TCGv_i32 t1, t2;
TCGv t1;
#endif
mb = MB(ctx->opcode);
@ -1706,14 +1706,11 @@ static void gen_rlwnm(DisasContext *ctx)
t0 = tcg_temp_new();
tcg_gen_andi_tl(t0, cpu_gpr[rB(ctx->opcode)], 0x1f);
#if defined(TARGET_PPC64)
t1 = tcg_temp_new_i32();
t2 = tcg_temp_new_i32();
tcg_gen_trunc_i64_i32(t1, cpu_gpr[rS(ctx->opcode)]);
tcg_gen_trunc_i64_i32(t2, t0);
tcg_gen_rotl_i32(t1, t1, t2);
tcg_gen_extu_i32_i64(t0, t1);
tcg_temp_free_i32(t1);
tcg_temp_free_i32(t2);
t1 = tcg_temp_new_i64();
tcg_gen_deposit_i64(t1, cpu_gpr[rS(ctx->opcode)],
cpu_gpr[rS(ctx->opcode)], 32, 32);
tcg_gen_rotl_i64(t0, t1, t0);
tcg_temp_free_i64(t1);
#else
tcg_gen_rotl_i32(t0, cpu_gpr[rS(ctx->opcode)], t0);
#endif
@ -1724,6 +1721,9 @@ static void gen_rlwnm(DisasContext *ctx)
#endif
tcg_gen_andi_tl(cpu_gpr[rA(ctx->opcode)], t0, MASK(mb, me));
} else {
#if defined(TARGET_PPC64)
tcg_gen_andi_tl(t0, t0, MASK(32, 63));
#endif
tcg_gen_mov_tl(cpu_gpr[rA(ctx->opcode)], t0);
}
tcg_temp_free(t0);