[Bug target/100152] New: Possible 10.3 bad code generation regression from 10.2/9.3 on Mac OS 10.15.7 (Catalina)

["lucier at math dot purdue.edu" <gcc-bugzilla@gcc.gnu.org>]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=100152

            Bug ID: 100152
           Summary: Possible 10.3 bad code generation regression from
                    10.2/9.3 on Mac OS 10.15.7 (Catalina)
           Product: gcc
           Version: 10.3.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: lucier at math dot purdue.edu
  Target Milestone: ---

With this compiler:

[Bradleys-Mac-mini:~] lucier% /usr/local/gcc-10.3.0/bin/gcc -v
Using built-in specs.
COLLECT_GCC=/usr/local/gcc-10.3.0/bin/gcc
COLLECT_LTO_WRAPPER=/usr/local/gcc-10.3.0/libexec/gcc/x86_64-apple-darwin19.6.0/10.3.0/lto-wrapper
Target: x86_64-apple-darwin19.6.0
Configured with: ../../gcc-10.3.0/configure --prefix=/usr/local/gcc-10.3.0
--enable-languages=c --disable-multilib --enable-checking=release
--with-sysroot=/Library/Developer/CommandLineTools/SDKs/MacOSX.sdk
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 10.3.0 (GCC) 

and these compiler options:

/usr/local/gcc-10.3.0/bin/gcc -save-temps -g -O3 -Wno-unused -Wno-write-strings
-Wdisabled-optimization -fwrapv -fno-strict-aliasing -fno-trapping-math
-fno-math-errno -fschedule-insns2 -fomit-frame-pointer -fPIC -fno-common -mpc64
  -I"../include" -c -o c_intf.o -I. -DHAVE_CONFIG_H
-D___GAMBITDIR="\"/usr/local/Gambit\""
-D___GAMBITDIR_USERLIB="\"~/.gambit_userlib\""
-D___GAMBITDIR_INSTLIB="\"~~userlib\"" -D___SYS_TYPE_CPU="\"x86_64\""
-D___SYS_TYPE_VENDOR="\"apple\"" -D___SYS_TYPE_OS="\"darwin19.6.0\""
-D___CONFIGURE_COMMAND="\"./configure 'CC=/usr/local/gcc-10.3.0/bin/gcc
-save-temps -g' '--enable-single-host' '--enable-shared'"\"
-D___OBJ_EXTENSION="\".o\"" -D___EXE_EXTENSION="\"\"" -D___BAT_EXTENSION="\"\""
-D___PRIMAL c_intf.c -D___LIBRARY

on Mac OS 10.5.7 (Catalina), I get a runtime failure, with console message:

Exception Type:        EXC_BAD_INSTRUCTION (SIGILL)
Exception Codes:       0x000000000000000c, 0x0000000000000000
Exception Note:        EXC_CORPSE_NOTIFY

Termination Signal:    Illegal instruction: 4
Termination Reason:    Namespace SIGNAL, Code 0x4
Terminating Process:   exc handler [98080]

Application Specific Information:
dyld2 mode

Thread 0 Crashed:: Dispatch queue: com.apple.main-thread
0   libgambit.dylib                     0x000000010dfaf010
___SCMOBJ_to_NONNULLSTRING + 1520 (c_intf.c:3280)

The disassembly (with arrow pointing to the noted instruction) is: 

(lldb) di -s 0x0000000103d60000 -c 10
libgambit.dylib`___SCMOBJ_to_NONNULLSTRING:
    0x103d60000 <+1504>: jl     0x103d60026               ; <+1542> at
c_intf.c:3282:9
    0x103d60002 <+1506>: orb    %al, 0x31(%rbp)
    0x103d60005 <+1509>: shlb   %cl, 0x2e(%rsi)
    0x103d60008 <+1512>: nopl   (%rax,%rax)
->  0x103d60010 <+1520>: movl   (%rbp,%r10,4), %esi
    0x103d60015 <+1525>: callq  0x103fba9a0               ; symbol stub for:
___UTF_8_put
    0x103d6001a <+1530>: movq   %r10, %rax
    0x103d6001d <+1533>: addq   $0x1, %r10
    0x103d60021 <+1537>: cmpq   %r12, %rax
    0x103d60024 <+1540>: jne    0x103d60010               ; <+1520> at
c_intf.c:3280:173

I'll add the .i and .s files.  I apologize for their length, I don't know how
much I can cut out and still keep them relevant.