https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69666
Bug ID: 69666 Summary: gcc ICE at -O2 and -O3 on valid code on x86_64-linux-gnu in "verify_gimple failed" Product: gcc Version: 6.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: tree-optimization Assignee: unassigned at gcc dot gnu.org Reporter: helloqirun at gmail dot com Target Milestone: --- The following valid code causes an ICE when compiled with the current gcc trunk at only -O2 and -O3 on x86_64-linux-gnu in both 32-bit and 64-bit modes. $ gcc-trunk -v Using built-in specs. COLLECT_GCC=gcc-trunk COLLECT_LTO_WRAPPER=/home/absozero/trunk/root-gcc/libexec/gcc/x86_64-pc-linux-gnu/6.0.0/lto-wrapper Target: x86_64-pc-linux-gnu Configured with: ../gcc/configure --prefix=/home/absozero/trunk/root-gcc --enable-languages=c,c++ --disable-werror --enable-multilib Thread model: posix gcc version 6.0.0 20160203 (experimental) [trunk revision 233104] (GCC) $ gcc-trunk abc.c -O2 abc.c: In function 'fun2': abc.c:13:1: error: conversion of register to a different size } ^ VIEW_CONVERT_EXPR<unsigned char>(e_10(D)); _4 = VIEW_CONVERT_EXPR<unsigned char>(e_10(D)); abc.c:13:1: internal compiler error: verify_gimple failed 0xba0056 verify_gimple_in_cfg(function*, bool) ../../gcc/gcc/tree-cfg.c:5125 0xa935d7 execute_function_todo ../../gcc/gcc/passes.c:1958 0xa93ecb execute_todo ../../gcc/gcc/passes.c:2010 Please submit a full bug report, with preprocessed source if appropriate. Please include the complete backtrace with any bug report. See <http://gcc.gnu.org/bugs.html> for instructions. $ cat abc.c int a, c, d; float b; void *memcpy(); int fun1(int p1, unsigned char *p2) { p2[p1] = b; return a; } void fun2() { unsigned char e[16]; fun1(16, e); d = e[d]; memcpy(&c, e, sizeof(e)); }