diff options
Diffstat (limited to 'gcc/config/i860/x-sysv4')
| -rw-r--r-- | gcc/config/i860/x-sysv4 | 26 |
1 files changed, 22 insertions, 4 deletions
diff --git a/gcc/config/i860/x-sysv4 b/gcc/config/i860/x-sysv4 index c766d9de..f480a57 100644 --- a/gcc/config/i860/x-sysv4 +++ b/gcc/config/i860/x-sysv4 @@ -9,9 +9,27 @@ INSTALL=cp # if we try to link programs with libucb.a before libc.a, those # programs tend to crash. -# More importantly, the alloca() routine supplied in early versions -# of svr4 for the i860 (in /usr/ucblib/libucb.a) is broken, so we -# should NOT try to use it anyway. +# Also, the alloca() routine supplied in early version of svr4 for +# the i860 is non-ABI compliant. It doesn't keep the stack aligned +# to a 16-byte boundary as the ABI requires. + +# More importantly however, even a fully ABI compliant alloca() routine +# would fail to work correctly with some versions of the native svr4 C +# compiler currently being distributed for the i860 (as of 1/29/92). +# The problem is that the native C compiler generates non-ABI-compliant +# function epilogues which cut back the stack (upon function exit) in +# an incorrect manner. Specifically, they cut back the stack by adding +# the nominal *static* frame size (determined statically at compile-time) +# to the stack pointer rather than setting the stack pointer based upon +# the current value of the frame pointer (as called for in the i860 ABI). +# This can cause serious trouble in cases where you repeatedly call a +# routine which itself calls alloca(). In such cases, the stack will +# grow continuously until you finally run out of swap space or exceed +# the system's process size limit. To avoid this problem (which can +# arise when a stage1 gcc is being used to build a stage2 gcc) you +# *must* link in the C language version of alloca() which is supplied +# with gcc to your stage1 version of gcc. The following definition +# forces that to happen. ALLOCA=alloca.o @@ -23,7 +41,7 @@ ALLOCA=alloca.o # i860 recognizes a special -gg option. Using that option causes *full* # Dwarf debugging information to be generated, whereas using only -g # causes only limited Dwarf debugging information to be generated. -# (This is an undocumented feature of that compiler.) +# (This is an undocumented feature of the native svr4 C compiler.) CCLIBFLAGS=-Bstatic -dn -gg GCC_CFLAGS=-static -g -O2 -B./ |