Commit 7e8fafbf authored by Richard Henderson's avatar Richard Henderson Committed by Peter Maydell
Browse files

target/arm: Fix SVE signed division vs x86 overflow exception 



We already check for the same condition within the normal integer
sdiv and sdiv64 helpers.  Use a slightly different formation that
does not require deducing the expression type.

Fixes: f97cfd59
Signed-off-by: default avatarRichard Henderson <richard.henderson@linaro.org>
Reviewed-by: default avatarPhilippe Mathieu-Daudé <f4bug@amsat.org>
Reviewed-by: default avatarPeter Maydell <peter.maydell@linaro.org>
Message-id: 20180629001538.11415-2-richard.henderson@linaro.org
[PMM: reworded a comment]
Signed-off-by: default avatarPeter Maydell <peter.maydell@linaro.org>
parent b3141c06

target/arm/sve_helper.c

+15 −5
Original line number Diff line number Diff line
@@ -369,7 +369,17 @@ void HELPER(NAME)(void *vd, void *vn, void *vm, void *vg, uint32_t desc) \ 
#define DO_MIN(N, M)  ((N) >= (M) ? (M) : (N))

#define DO_ABD(N, M)  ((N) >= (M) ? (N) - (M) : (M) - (N))

#define DO_MUL(N, M)  (N * M)

#define DO_DIV(N, M)  (M ? N / M : 0)





/*

 * We must avoid the C undefined behaviour cases: division by

 * zero and signed division of INT_MIN by -1. Both of these

 * have architecturally defined required results for Arm.

 * We special case all signed divisions by -1 to avoid having

 * to deduce the minimum integer for the type involved.

 */

#define DO_SDIV(N, M) (unlikely(M == 0) ? 0 : unlikely(M == -1) ? -N : N / M)

#define DO_UDIV(N, M) (unlikely(M == 0) ? 0 : N / M)



DO_ZPZZ(sve_and_zpzz_b, uint8_t, H1, DO_AND)

DO_ZPZZ(sve_and_zpzz_h, uint16_t, H1_2, DO_AND)
@@ -477,11 +487,11 @@ DO_ZPZZ(sve_umulh_zpzz_h, uint16_t, H1_2, do_mulh_h) 
DO_ZPZZ(sve_umulh_zpzz_s, uint32_t, H1_4, do_mulh_s)

DO_ZPZZ_D(sve_umulh_zpzz_d, uint64_t, do_umulh_d)



DO_ZPZZ(sve_sdiv_zpzz_s, int32_t, H1_4, DO_DIV)

DO_ZPZZ_D(sve_sdiv_zpzz_d, int64_t, DO_DIV)

DO_ZPZZ(sve_sdiv_zpzz_s, int32_t, H1_4, DO_SDIV)

DO_ZPZZ_D(sve_sdiv_zpzz_d, int64_t, DO_SDIV)



DO_ZPZZ(sve_udiv_zpzz_s, uint32_t, H1_4, DO_DIV)

DO_ZPZZ_D(sve_udiv_zpzz_d, uint64_t, DO_DIV)

DO_ZPZZ(sve_udiv_zpzz_s, uint32_t, H1_4, DO_UDIV)

DO_ZPZZ_D(sve_udiv_zpzz_d, uint64_t, DO_UDIV)



/* Note that all bits of the shift are significant

   and not modulo the element size.  */