https://gcc.gnu.org/PR90419

diff -ruN gcc-8.3.0.orig/gcc/config/riscv/t-linux-multilib gcc-8.3.0/gcc/config/riscv/t-linux-multilib
--- gcc-8.3.0.orig/gcc/config/riscv/t-linux-multilib	2017-02-06 22:38:37.000000000 +0100
+++ gcc-8.3.0/gcc/config/riscv/t-linux-multilib	2019-04-28 16:37:44.377841943 +0200
@@ -20,21 +20,9 @@
 ilp32d \
 lp64 \
 lp64d
-MULTILIB_REQUIRED = march=rv32imac/mabi=ilp32 \
-march=rv32imafdc/mabi=ilp32d \
-march=rv64imac/mabi=lp64 \
+MULTILIB_REQUIRED = march=rv64imac/mabi=lp64 \
 march=rv64imafdc/mabi=lp64d
-MULTILIB_REUSE = march.rv32imac/mabi.ilp32=march.rv32ima/mabi.ilp32 \
-march.rv32imac/mabi.ilp32=march.rv32imaf/mabi.ilp32 \
-march.rv32imac/mabi.ilp32=march.rv32imafd/mabi.ilp32 \
-march.rv32imac/mabi.ilp32=march.rv32imafc/mabi.ilp32 \
-march.rv32imac/mabi.ilp32=march.rv32imafdc/mabi.ilp32 \
-march.rv32imac/mabi.ilp32=march.rv32g/mabi.ilp32 \
-march.rv32imac/mabi.ilp32=march.rv32gc/mabi.ilp32 \
-march.rv32imafdc/mabi.ilp32d=march.rv32imafd/mabi.ilp32d \
-march.rv32imafdc/mabi.ilp32d=march.rv32gc/mabi.ilp32d \
-march.rv32imafdc/mabi.ilp32d=march.rv32g/mabi.ilp32d \
-march.rv64imac/mabi.lp64=march.rv64ima/mabi.lp64 \
+MULTILIB_REUSE = march.rv64imac/mabi.lp64=march.rv64ima/mabi.lp64 \
 march.rv64imac/mabi.lp64=march.rv64imaf/mabi.lp64 \
 march.rv64imac/mabi.lp64=march.rv64imafd/mabi.lp64 \
 march.rv64imac/mabi.lp64=march.rv64imafc/mabi.lp64 \