tests/tcg/ppc64le: drop __int128 usage in bcdsub

Using __int128 with inline asm constraints like "v" generates incorrect
code when compiling with LLVM/Clang (e.g., only one doubleword of the
VSR is loaded). Instead, use a GPR pair to pass the 128-bits value and
load the VSR with mtvsrd/xxmrghd.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Signed-off-by: Matheus Ferst <matheus.ferst@eldorado.org.br>
Message-Id: <20220304165417.1981159-4-matheus.ferst@eldorado.org.br>
Signed-off-by: Cédric Le Goater <clg@kaod.org>
This commit is contained in:
Matheus Ferst 2022-03-05 07:16:46 +01:00 committed by Cédric Le Goater
parent 4e4b5a3eac
commit 8189cb8507
1 changed files with 58 additions and 65 deletions

View File

@ -1,6 +1,7 @@
#include <assert.h>
#include <unistd.h>
#include <signal.h>
#include <stdint.h>
#define CRF_LT (1 << 3)
#define CRF_GT (1 << 2)
@ -8,24 +9,39 @@
#define CRF_SO (1 << 0)
#define UNDEF 0
#define BCDSUB(vra, vrb, ps) \
asm ("bcdsub. %1,%2,%3,%4;" \
"mfocrf %0,0b10;" \
: "=r" (cr), "=v" (vrt) \
: "v" (vra), "v" (vrb), "i" (ps) \
: );
/*
* Use GPR pairs to load the VSR values and place the resulting VSR and CR6 in
* th, tl, and cr. Note that we avoid newer instructions (e.g., mtvsrdd/mfvsrld)
* so we can run this test on POWER8 machines.
*/
#define BCDSUB(AH, AL, BH, BL, PS) \
asm ("mtvsrd 32, %3\n\t" \
"mtvsrd 33, %4\n\t" \
"xxmrghd 32, 32, 33\n\t" \
"mtvsrd 33, %5\n\t" \
"mtvsrd 34, %6\n\t" \
"xxmrghd 33, 33, 34\n\t" \
"bcdsub. 0, 0, 1, %7\n\t" \
"mfocrf %0, 0b10\n\t" \
"mfvsrd %1, 32\n\t" \
"xxswapd 32, 32\n\t" \
"mfvsrd %2, 32\n\t" \
: "=r" (cr), "=r" (th), "=r" (tl) \
: "r" (AH), "r" (AL), "r" (BH), "r" (BL), "i" (PS) \
: "v0", "v1", "v2");
#define TEST(vra, vrb, ps, exp_res, exp_cr6) \
#define TEST(AH, AL, BH, BL, PS, TH, TL, CR6) \
do { \
__int128 vrt = 0; \
int cr = 0; \
BCDSUB(vra, vrb, ps); \
if (exp_res) \
assert(vrt == exp_res); \
assert((cr >> 4) == exp_cr6); \
uint64_t th, tl; \
BCDSUB(AH, AL, BH, BL, PS); \
if (TH != UNDEF || TL != UNDEF) { \
assert(tl == TL); \
assert(th == TH); \
} \
assert((cr >> 4) == CR6); \
} while (0)
/*
* Unbounded result is equal to zero:
* sign = (PS) ? 0b1111 : 0b1100
@ -33,13 +49,13 @@
*/
void test_bcdsub_eq(void)
{
__int128 a, b;
/* maximum positive BCD value */
a = b = (((__int128) 0x9999999999999999) << 64 | 0x999999999999999c);
TEST(a, b, 0, 0xc, CRF_EQ);
TEST(a, b, 1, 0xf, CRF_EQ);
TEST(0x9999999999999999, 0x999999999999999c,
0x9999999999999999, 0x999999999999999c,
0, 0x0, 0xc, CRF_EQ);
TEST(0x9999999999999999, 0x999999999999999c,
0x9999999999999999, 0x999999999999999c,
1, 0x0, 0xf, CRF_EQ);
}
/*
@ -49,21 +65,16 @@ void test_bcdsub_eq(void)
*/
void test_bcdsub_gt(void)
{
__int128 a, b, c;
/* maximum positive and negative one BCD values */
TEST(0x9999999999999999, 0x999999999999999c, 0x0, 0x1d, 0,
0x0, 0xc, (CRF_GT | CRF_SO));
TEST(0x9999999999999999, 0x999999999999999c, 0x0, 0x1d, 1,
0x0, 0xf, (CRF_GT | CRF_SO));
/* maximum positive BCD value */
a = (((__int128) 0x9999999999999999) << 64 | 0x999999999999999c);
/* negative one BCD value */
b = (__int128) 0x1d;
TEST(a, b, 0, 0xc, (CRF_GT | CRF_SO));
TEST(a, b, 1, 0xf, (CRF_GT | CRF_SO));
c = (((__int128) 0x9999999999999999) << 64 | 0x999999999999998c);
TEST(c, b, 0, a, CRF_GT);
TEST(c, b, 1, (a | 0x3), CRF_GT);
TEST(0x9999999999999999, 0x999999999999998c, 0x0, 0x1d, 0,
0x9999999999999999, 0x999999999999999c, CRF_GT);
TEST(0x9999999999999999, 0x999999999999998c, 0x0, 0x1d, 1,
0x9999999999999999, 0x999999999999999f, CRF_GT);
}
/*
@ -73,45 +84,27 @@ void test_bcdsub_gt(void)
*/
void test_bcdsub_lt(void)
{
__int128 a, b;
/* positive zero and positive one BCD values */
TEST(0x0, 0xc, 0x0, 0x1c, 0, 0x0, 0x1d, CRF_LT);
TEST(0x0, 0xc, 0x0, 0x1c, 1, 0x0, 0x1d, CRF_LT);
/* positive zero BCD value */
a = (__int128) 0xc;
/* positive one BCD value */
b = (__int128) 0x1c;
TEST(a, b, 0, 0x1d, CRF_LT);
TEST(a, b, 1, 0x1d, CRF_LT);
/* maximum negative BCD value */
a = (((__int128) 0x9999999999999999) << 64 | 0x999999999999999d);
/* positive one BCD value */
b = (__int128) 0x1c;
TEST(a, b, 0, 0xd, (CRF_LT | CRF_SO));
TEST(a, b, 1, 0xd, (CRF_LT | CRF_SO));
/* maximum negative and positive one BCD values */
TEST(0x9999999999999999, 0x999999999999999d, 0x0, 0x1c, 0,
0x0, 0xd, (CRF_LT | CRF_SO));
TEST(0x9999999999999999, 0x999999999999999d, 0x0, 0x1c, 1,
0x0, 0xd, (CRF_LT | CRF_SO));
}
void test_bcdsub_invalid(void)
{
__int128 a, b;
TEST(0x0, 0x1c, 0x0, 0xf00, 0, UNDEF, UNDEF, CRF_SO);
TEST(0x0, 0x1c, 0x0, 0xf00, 1, UNDEF, UNDEF, CRF_SO);
/* positive one BCD value */
a = (__int128) 0x1c;
b = 0xf00;
TEST(0x0, 0xf00, 0x0, 0x1c, 0, UNDEF, UNDEF, CRF_SO);
TEST(0x0, 0xf00, 0x0, 0x1c, 1, UNDEF, UNDEF, CRF_SO);
TEST(a, b, 0, UNDEF, CRF_SO);
TEST(a, b, 1, UNDEF, CRF_SO);
TEST(b, a, 0, UNDEF, CRF_SO);
TEST(b, a, 1, UNDEF, CRF_SO);
a = 0xbad;
TEST(a, b, 0, UNDEF, CRF_SO);
TEST(a, b, 1, UNDEF, CRF_SO);
TEST(0x0, 0xbad, 0x0, 0xf00, 0, UNDEF, UNDEF, CRF_SO);
TEST(0x0, 0xbad, 0x0, 0xf00, 1, UNDEF, UNDEF, CRF_SO);
}
int main(void)