| Message ID | 20200501190913.25008-2-dbuono@linux.vnet.ibm.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
| Series | target-ppc: fix rlwimi, rlwinm, rlwnm for Clang-9 | expand |
On Fri, May 01, 2020 at 03:09:13PM -0400, Daniele Buono wrote: > Starting with Clang v9, -Wtype-limits is implemented and triggers a > few "result of comparison is always true" errors when compiling PPC32 > targets. > > The comparisons seem to be necessary only on PPC64, since the > else branch in PPC32 only has a "g_assert_not_reached();" in all cases. > > This patch restructures the code so that PPC32 does not execute the > check, while PPC64 works like before > > Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com> Urgh. #ifdefs intertangled with if statements gets pretty ugly. But, then, it's already pretty ugly, so, applied. > --- > target/ppc/translate.c | 34 +++++++++++++++++++--------------- > 1 file changed, 19 insertions(+), 15 deletions(-) > > diff --git a/target/ppc/translate.c b/target/ppc/translate.c > index 807d14faaa..9400fa2c7c 100644 > --- a/target/ppc/translate.c > +++ b/target/ppc/translate.c > @@ -1882,6 +1882,7 @@ static void gen_rlwimi(DisasContext *ctx) > tcg_gen_deposit_tl(t_ra, t_ra, t_rs, sh, me - mb + 1); > } else { > target_ulong mask; > + TCGv_i32 t0; > TCGv t1; > > #if defined(TARGET_PPC64) > @@ -1891,20 +1892,20 @@ static void gen_rlwimi(DisasContext *ctx) > mask = MASK(mb, me); > > t1 = tcg_temp_new(); > +#if defined(TARGET_PPC64) > if (mask <= 0xffffffffu) { > - TCGv_i32 t0 = tcg_temp_new_i32(); > +#endif > + t0 = tcg_temp_new_i32(); > tcg_gen_trunc_tl_i32(t0, t_rs); > tcg_gen_rotli_i32(t0, t0, sh); > tcg_gen_extu_i32_tl(t1, t0); > tcg_temp_free_i32(t0); > - } else { > #if defined(TARGET_PPC64) > + } else { > tcg_gen_deposit_i64(t1, t_rs, t_rs, 32, 32); > tcg_gen_rotli_i64(t1, t1, sh); > -#else > - g_assert_not_reached(); > -#endif > } > +#endif > > tcg_gen_andi_tl(t1, t1, mask); > tcg_gen_andi_tl(t_ra, t_ra, ~mask); > @@ -1938,7 +1939,9 @@ static void gen_rlwinm(DisasContext *ctx) > me += 32; > #endif > mask = MASK(mb, me); > +#if defined(TARGET_PPC64) > if (mask <= 0xffffffffu) { > +#endif > if (sh == 0) { > tcg_gen_andi_tl(t_ra, t_rs, mask); > } else { > @@ -1949,15 +1952,13 @@ static void gen_rlwinm(DisasContext *ctx) > tcg_gen_extu_i32_tl(t_ra, t0); > tcg_temp_free_i32(t0); > } > - } else { > #if defined(TARGET_PPC64) > + } else { > tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); > tcg_gen_rotli_i64(t_ra, t_ra, sh); > tcg_gen_andi_i64(t_ra, t_ra, mask); > -#else > - g_assert_not_reached(); > -#endif > } > +#endif > } > if (unlikely(Rc(ctx->opcode) != 0)) { > gen_set_Rc0(ctx, t_ra); > @@ -1972,6 +1973,9 @@ static void gen_rlwnm(DisasContext *ctx) > TCGv t_rb = cpu_gpr[rB(ctx->opcode)]; > uint32_t mb = MB(ctx->opcode); > uint32_t me = ME(ctx->opcode); > + TCGv_i32 t0; > + TCGv_i32 t1; > + > target_ulong mask; > > #if defined(TARGET_PPC64) > @@ -1980,9 +1984,11 @@ static void gen_rlwnm(DisasContext *ctx) > #endif > mask = MASK(mb, me); > > +#if defined(TARGET_PPC64) > if (mask <= 0xffffffffu) { > - TCGv_i32 t0 = tcg_temp_new_i32(); > - TCGv_i32 t1 = tcg_temp_new_i32(); > +#endif > + t0 = tcg_temp_new_i32(); > + t1 = tcg_temp_new_i32(); > tcg_gen_trunc_tl_i32(t0, t_rb); > tcg_gen_trunc_tl_i32(t1, t_rs); > tcg_gen_andi_i32(t0, t0, 0x1f); > @@ -1990,17 +1996,15 @@ static void gen_rlwnm(DisasContext *ctx) > tcg_gen_extu_i32_tl(t_ra, t1); > tcg_temp_free_i32(t0); > tcg_temp_free_i32(t1); > - } else { > #if defined(TARGET_PPC64) > + } else { > TCGv_i64 t0 = tcg_temp_new_i64(); > tcg_gen_andi_i64(t0, t_rb, 0x1f); > tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); > tcg_gen_rotl_i64(t_ra, t_ra, t0); > tcg_temp_free_i64(t0); > -#else > - g_assert_not_reached(); > -#endif > } > +#endif > > tcg_gen_andi_tl(t_ra, t_ra, mask); >
On 5/5/2020 1:08 AM, David Gibson wrote: > On Fri, May 01, 2020 at 03:09:13PM -0400, Daniele Buono wrote: >> Starting with Clang v9, -Wtype-limits is implemented and triggers a >> few "result of comparison is always true" errors when compiling PPC32 >> targets. >> >> The comparisons seem to be necessary only on PPC64, since the >> else branch in PPC32 only has a "g_assert_not_reached();" in all cases. >> >> This patch restructures the code so that PPC32 does not execute the >> check, while PPC64 works like before >> >> Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com> > > Urgh. #ifdefs intertangled with if statements gets pretty ugly. But, > then, it's already pretty ugly, so, applied. > Agreed, it's very ugly. After I sent the patch I thought of an alternative that looks like this: bool mask_in_32b = true; #if defined(TARGET_PPC64) if (mask > 0xffffffffu) mask_in_32b = false; #endif if (mask_in_32b) { /* Original if-else untouched using mask_in_32b instead of mask*/ It does have an additional if, but with a bit of luck the compiler may optimize it out (at least for the 32bit case). If you think the final outcome may be better, let me know and I'll send a patch v2 like that. >> --- >> target/ppc/translate.c | 34 +++++++++++++++++++--------------- >> 1 file changed, 19 insertions(+), 15 deletions(-) >> >> diff --git a/target/ppc/translate.c b/target/ppc/translate.c >> index 807d14faaa..9400fa2c7c 100644 >> --- a/target/ppc/translate.c >> +++ b/target/ppc/translate.c >> @@ -1882,6 +1882,7 @@ static void gen_rlwimi(DisasContext *ctx) >> tcg_gen_deposit_tl(t_ra, t_ra, t_rs, sh, me - mb + 1); >> } else { >> target_ulong mask; >> + TCGv_i32 t0; >> TCGv t1; >> >> #if defined(TARGET_PPC64) >> @@ -1891,20 +1892,20 @@ static void gen_rlwimi(DisasContext *ctx) >> mask = MASK(mb, me); >> >> t1 = tcg_temp_new(); >> +#if defined(TARGET_PPC64) >> if (mask <= 0xffffffffu) { >> - TCGv_i32 t0 = tcg_temp_new_i32(); >> +#endif >> + t0 = tcg_temp_new_i32(); >> tcg_gen_trunc_tl_i32(t0, t_rs); >> tcg_gen_rotli_i32(t0, t0, sh); >> tcg_gen_extu_i32_tl(t1, t0); >> tcg_temp_free_i32(t0); >> - } else { >> #if defined(TARGET_PPC64) >> + } else { >> tcg_gen_deposit_i64(t1, t_rs, t_rs, 32, 32); >> tcg_gen_rotli_i64(t1, t1, sh); >> -#else >> - g_assert_not_reached(); >> -#endif >> } >> +#endif >> >> tcg_gen_andi_tl(t1, t1, mask); >> tcg_gen_andi_tl(t_ra, t_ra, ~mask); >> @@ -1938,7 +1939,9 @@ static void gen_rlwinm(DisasContext *ctx) >> me += 32; >> #endif >> mask = MASK(mb, me); >> +#if defined(TARGET_PPC64) >> if (mask <= 0xffffffffu) { >> +#endif >> if (sh == 0) { >> tcg_gen_andi_tl(t_ra, t_rs, mask); >> } else { >> @@ -1949,15 +1952,13 @@ static void gen_rlwinm(DisasContext *ctx) >> tcg_gen_extu_i32_tl(t_ra, t0); >> tcg_temp_free_i32(t0); >> } >> - } else { >> #if defined(TARGET_PPC64) >> + } else { >> tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); >> tcg_gen_rotli_i64(t_ra, t_ra, sh); >> tcg_gen_andi_i64(t_ra, t_ra, mask); >> -#else >> - g_assert_not_reached(); >> -#endif >> } >> +#endif >> } >> if (unlikely(Rc(ctx->opcode) != 0)) { >> gen_set_Rc0(ctx, t_ra); >> @@ -1972,6 +1973,9 @@ static void gen_rlwnm(DisasContext *ctx) >> TCGv t_rb = cpu_gpr[rB(ctx->opcode)]; >> uint32_t mb = MB(ctx->opcode); >> uint32_t me = ME(ctx->opcode); >> + TCGv_i32 t0; >> + TCGv_i32 t1; >> + >> target_ulong mask; >> >> #if defined(TARGET_PPC64) >> @@ -1980,9 +1984,11 @@ static void gen_rlwnm(DisasContext *ctx) >> #endif >> mask = MASK(mb, me); >> >> +#if defined(TARGET_PPC64) >> if (mask <= 0xffffffffu) { >> - TCGv_i32 t0 = tcg_temp_new_i32(); >> - TCGv_i32 t1 = tcg_temp_new_i32(); >> +#endif >> + t0 = tcg_temp_new_i32(); >> + t1 = tcg_temp_new_i32(); >> tcg_gen_trunc_tl_i32(t0, t_rb); >> tcg_gen_trunc_tl_i32(t1, t_rs); >> tcg_gen_andi_i32(t0, t0, 0x1f); >> @@ -1990,17 +1996,15 @@ static void gen_rlwnm(DisasContext *ctx) >> tcg_gen_extu_i32_tl(t_ra, t1); >> tcg_temp_free_i32(t0); >> tcg_temp_free_i32(t1); >> - } else { >> #if defined(TARGET_PPC64) >> + } else { >> TCGv_i64 t0 = tcg_temp_new_i64(); >> tcg_gen_andi_i64(t0, t_rb, 0x1f); >> tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); >> tcg_gen_rotl_i64(t_ra, t_ra, t0); >> tcg_temp_free_i64(t0); >> -#else >> - g_assert_not_reached(); >> -#endif >> } >> +#endif >> >> tcg_gen_andi_tl(t_ra, t_ra, mask); >> >
On Tue, May 05, 2020 at 08:26:48AM -0400, Daniele Buono wrote: > On 5/5/2020 1:08 AM, David Gibson wrote: > > On Fri, May 01, 2020 at 03:09:13PM -0400, Daniele Buono wrote: > > > Starting with Clang v9, -Wtype-limits is implemented and triggers a > > > few "result of comparison is always true" errors when compiling PPC32 > > > targets. > > > > > > The comparisons seem to be necessary only on PPC64, since the > > > else branch in PPC32 only has a "g_assert_not_reached();" in all cases. > > > > > > This patch restructures the code so that PPC32 does not execute the > > > check, while PPC64 works like before > > > > > > Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com> > > > > Urgh. #ifdefs intertangled with if statements gets pretty ugly. But, > > then, it's already pretty ugly, so, applied. > > > Agreed, it's very ugly. After I sent the patch I thought of an alternative > that looks like this: > > bool mask_in_32b = true; > > #if defined(TARGET_PPC64) > if (mask > 0xffffffffu) > mask_in_32b = false; > #endif > > if (mask_in_32b) { > /* Original if-else untouched using mask_in_32b instead of mask*/ > > It does have an additional if, but with a bit of luck the compiler may > optimize it out (at least for the 32bit case). > If you think the final outcome may be better, let me know and I'll send a > patch v2 like that. Yeah, that would be a bit nicer. Please send the v2. > > > > --- > > > target/ppc/translate.c | 34 +++++++++++++++++++--------------- > > > 1 file changed, 19 insertions(+), 15 deletions(-) > > > > > > diff --git a/target/ppc/translate.c b/target/ppc/translate.c > > > index 807d14faaa..9400fa2c7c 100644 > > > --- a/target/ppc/translate.c > > > +++ b/target/ppc/translate.c > > > @@ -1882,6 +1882,7 @@ static void gen_rlwimi(DisasContext *ctx) > > > tcg_gen_deposit_tl(t_ra, t_ra, t_rs, sh, me - mb + 1); > > > } else { > > > target_ulong mask; > > > + TCGv_i32 t0; > > > TCGv t1; > > > #if defined(TARGET_PPC64) > > > @@ -1891,20 +1892,20 @@ static void gen_rlwimi(DisasContext *ctx) > > > mask = MASK(mb, me); > > > t1 = tcg_temp_new(); > > > +#if defined(TARGET_PPC64) > > > if (mask <= 0xffffffffu) { > > > - TCGv_i32 t0 = tcg_temp_new_i32(); > > > +#endif > > > + t0 = tcg_temp_new_i32(); > > > tcg_gen_trunc_tl_i32(t0, t_rs); > > > tcg_gen_rotli_i32(t0, t0, sh); > > > tcg_gen_extu_i32_tl(t1, t0); > > > tcg_temp_free_i32(t0); > > > - } else { > > > #if defined(TARGET_PPC64) > > > + } else { > > > tcg_gen_deposit_i64(t1, t_rs, t_rs, 32, 32); > > > tcg_gen_rotli_i64(t1, t1, sh); > > > -#else > > > - g_assert_not_reached(); > > > -#endif > > > } > > > +#endif > > > tcg_gen_andi_tl(t1, t1, mask); > > > tcg_gen_andi_tl(t_ra, t_ra, ~mask); > > > @@ -1938,7 +1939,9 @@ static void gen_rlwinm(DisasContext *ctx) > > > me += 32; > > > #endif > > > mask = MASK(mb, me); > > > +#if defined(TARGET_PPC64) > > > if (mask <= 0xffffffffu) { > > > +#endif > > > if (sh == 0) { > > > tcg_gen_andi_tl(t_ra, t_rs, mask); > > > } else { > > > @@ -1949,15 +1952,13 @@ static void gen_rlwinm(DisasContext *ctx) > > > tcg_gen_extu_i32_tl(t_ra, t0); > > > tcg_temp_free_i32(t0); > > > } > > > - } else { > > > #if defined(TARGET_PPC64) > > > + } else { > > > tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); > > > tcg_gen_rotli_i64(t_ra, t_ra, sh); > > > tcg_gen_andi_i64(t_ra, t_ra, mask); > > > -#else > > > - g_assert_not_reached(); > > > -#endif > > > } > > > +#endif > > > } > > > if (unlikely(Rc(ctx->opcode) != 0)) { > > > gen_set_Rc0(ctx, t_ra); > > > @@ -1972,6 +1973,9 @@ static void gen_rlwnm(DisasContext *ctx) > > > TCGv t_rb = cpu_gpr[rB(ctx->opcode)]; > > > uint32_t mb = MB(ctx->opcode); > > > uint32_t me = ME(ctx->opcode); > > > + TCGv_i32 t0; > > > + TCGv_i32 t1; > > > + > > > target_ulong mask; > > > #if defined(TARGET_PPC64) > > > @@ -1980,9 +1984,11 @@ static void gen_rlwnm(DisasContext *ctx) > > > #endif > > > mask = MASK(mb, me); > > > +#if defined(TARGET_PPC64) > > > if (mask <= 0xffffffffu) { > > > - TCGv_i32 t0 = tcg_temp_new_i32(); > > > - TCGv_i32 t1 = tcg_temp_new_i32(); > > > +#endif > > > + t0 = tcg_temp_new_i32(); > > > + t1 = tcg_temp_new_i32(); > > > tcg_gen_trunc_tl_i32(t0, t_rb); > > > tcg_gen_trunc_tl_i32(t1, t_rs); > > > tcg_gen_andi_i32(t0, t0, 0x1f); > > > @@ -1990,17 +1996,15 @@ static void gen_rlwnm(DisasContext *ctx) > > > tcg_gen_extu_i32_tl(t_ra, t1); > > > tcg_temp_free_i32(t0); > > > tcg_temp_free_i32(t1); > > > - } else { > > > #if defined(TARGET_PPC64) > > > + } else { > > > TCGv_i64 t0 = tcg_temp_new_i64(); > > > tcg_gen_andi_i64(t0, t_rb, 0x1f); > > > tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); > > > tcg_gen_rotl_i64(t_ra, t_ra, t0); > > > tcg_temp_free_i64(t0); > > > -#else > > > - g_assert_not_reached(); > > > -#endif > > > } > > > +#endif > > > tcg_gen_andi_tl(t_ra, t_ra, mask); > > >
diff --git a/target/ppc/translate.c b/target/ppc/translate.c index 807d14faaa..9400fa2c7c 100644 --- a/target/ppc/translate.c +++ b/target/ppc/translate.c @@ -1882,6 +1882,7 @@ static void gen_rlwimi(DisasContext *ctx) tcg_gen_deposit_tl(t_ra, t_ra, t_rs, sh, me - mb + 1); } else { target_ulong mask; + TCGv_i32 t0; TCGv t1; #if defined(TARGET_PPC64) @@ -1891,20 +1892,20 @@ static void gen_rlwimi(DisasContext *ctx) mask = MASK(mb, me); t1 = tcg_temp_new(); +#if defined(TARGET_PPC64) if (mask <= 0xffffffffu) { - TCGv_i32 t0 = tcg_temp_new_i32(); +#endif + t0 = tcg_temp_new_i32(); tcg_gen_trunc_tl_i32(t0, t_rs); tcg_gen_rotli_i32(t0, t0, sh); tcg_gen_extu_i32_tl(t1, t0); tcg_temp_free_i32(t0); - } else { #if defined(TARGET_PPC64) + } else { tcg_gen_deposit_i64(t1, t_rs, t_rs, 32, 32); tcg_gen_rotli_i64(t1, t1, sh); -#else - g_assert_not_reached(); -#endif } +#endif tcg_gen_andi_tl(t1, t1, mask); tcg_gen_andi_tl(t_ra, t_ra, ~mask); @@ -1938,7 +1939,9 @@ static void gen_rlwinm(DisasContext *ctx) me += 32; #endif mask = MASK(mb, me); +#if defined(TARGET_PPC64) if (mask <= 0xffffffffu) { +#endif if (sh == 0) { tcg_gen_andi_tl(t_ra, t_rs, mask); } else { @@ -1949,15 +1952,13 @@ static void gen_rlwinm(DisasContext *ctx) tcg_gen_extu_i32_tl(t_ra, t0); tcg_temp_free_i32(t0); } - } else { #if defined(TARGET_PPC64) + } else { tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); tcg_gen_rotli_i64(t_ra, t_ra, sh); tcg_gen_andi_i64(t_ra, t_ra, mask); -#else - g_assert_not_reached(); -#endif } +#endif } if (unlikely(Rc(ctx->opcode) != 0)) { gen_set_Rc0(ctx, t_ra); @@ -1972,6 +1973,9 @@ static void gen_rlwnm(DisasContext *ctx) TCGv t_rb = cpu_gpr[rB(ctx->opcode)]; uint32_t mb = MB(ctx->opcode); uint32_t me = ME(ctx->opcode); + TCGv_i32 t0; + TCGv_i32 t1; + target_ulong mask; #if defined(TARGET_PPC64) @@ -1980,9 +1984,11 @@ static void gen_rlwnm(DisasContext *ctx) #endif mask = MASK(mb, me); +#if defined(TARGET_PPC64) if (mask <= 0xffffffffu) { - TCGv_i32 t0 = tcg_temp_new_i32(); - TCGv_i32 t1 = tcg_temp_new_i32(); +#endif + t0 = tcg_temp_new_i32(); + t1 = tcg_temp_new_i32(); tcg_gen_trunc_tl_i32(t0, t_rb); tcg_gen_trunc_tl_i32(t1, t_rs); tcg_gen_andi_i32(t0, t0, 0x1f); @@ -1990,17 +1996,15 @@ static void gen_rlwnm(DisasContext *ctx) tcg_gen_extu_i32_tl(t_ra, t1); tcg_temp_free_i32(t0); tcg_temp_free_i32(t1); - } else { #if defined(TARGET_PPC64) + } else { TCGv_i64 t0 = tcg_temp_new_i64(); tcg_gen_andi_i64(t0, t_rb, 0x1f); tcg_gen_deposit_i64(t_ra, t_rs, t_rs, 32, 32); tcg_gen_rotl_i64(t_ra, t_ra, t0); tcg_temp_free_i64(t0); -#else - g_assert_not_reached(); -#endif } +#endif tcg_gen_andi_tl(t_ra, t_ra, mask);
Starting with Clang v9, -Wtype-limits is implemented and triggers a few "result of comparison is always true" errors when compiling PPC32 targets. The comparisons seem to be necessary only on PPC64, since the else branch in PPC32 only has a "g_assert_not_reached();" in all cases. This patch restructures the code so that PPC32 does not execute the check, while PPC64 works like before Signed-off-by: Daniele Buono <dbuono@linux.vnet.ibm.com> --- target/ppc/translate.c | 34 +++++++++++++++++++--------------- 1 file changed, 19 insertions(+), 15 deletions(-)