With gcc version 4.3.0 20071024 (experimental) [trunk revision 129615] configured: ../trunk/configure --enable-languages=c,c++,java --disable-static --enable-__cxa_atexit --prefix=/home/daney/mvl_ti/gcj --with-gmp=/home/daney/mp --with-mpfr=/home/daney/mp --with-sysroot=/home/daney/mvl_ti/mv_pro_4.0/montavista/pro/devkit/arm/v5t_le/target --with-float=soft --disable-java-awt --without-x --disable-jvmpi --disable-sjlj-exceptions --target=armv5tl-montavista-linuxeabi If the last fixed argument in a va_arg function is 64 bits bad things happen. Here is the test program: --------8<--------- #include <stdio.h> #include <stdarg.h> #include <stdint.h> class A { private: int foo; public: A(int a) { foo = a; } void f(int64_t j,...); void f2(int64_t j, int l,...); void f1(int64_t j); void g(int j,...); void h(int j, va_list ap); }; void A::f(int64_t j,...) { va_list ap; va_start(ap, j); int k = va_arg(ap, int); h(5, ap); va_end(ap); printf("A::f %d %lld, sizeof(j) = %d\n", k, j, sizeof(j)); } void A::f2(int64_t j, int l, ...) { va_list ap; va_start(ap, l); int k = va_arg(ap, int); h(5, ap); va_end(ap); printf("A::f2 %d %lld, sizeof(j) = %d\n", k, j, sizeof(j)); } void A::f1(int64_t j) { printf("A::f1 %lld, sizeof(j) = %d\n", j, sizeof(j)); } void A::g(int j,...) { va_list ap; va_start(ap, j); int k = va_arg(ap, int); h(7, ap); va_end(ap); printf("A::f %d %d\n", k, j); } void A::h(int j, va_list ap) { int k; do { k = va_arg(ap, int); printf(" A::h %d - %d\n", j, k); } while (k >= 0); } int main(int argc, char *argv[]) { A *a = new A(9); a->f(300, 4,6,8,10,-1); a->f2(300, 99, 4,6,8,10,-1); a->g(400, 3,5,7,9,11,13,-1); a->f1(500); } -------8<---------- Expected output: $ ./vargs A::h 5 - 6 A::h 5 - 8 A::h 5 - 10 A::h 5 - -1 A::f 4 300, sizeof(j) = 8 A::h 5 - 6 A::h 5 - 8 A::h 5 - 10 A::h 5 - -1 A::f2 4 300, sizeof(j) = 8 A::h 7 - 5 A::h 7 - 7 A::h 7 - 9 A::h 7 - 11 A::h 7 - 13 A::h 7 - -1 A::f 3 400 A::f1 500, sizeof(j) = 8 Output on armv5tl-none-linuxeabi: # ./vargs A::h 5 - 4 A::h 5 - 6 A::h 5 - 8 A::h 5 - 10 A::h 5 - -1 A::f 0 1288490188809, sizeof(j) = 8 A::h 5 - 6 A::h 5 - 8 A::h 5 - 10 A::h 5 - -1 A::f2 4 300, sizeof(j) = 8 A::h 7 - 5 A::h 7 - 7 A::h 7 - 9 A::h 7 - 11 A::h 7 - 13 A::h 7 - -1 A::f 3 400 A::f1 500, sizeof(j) = 8 Note that output 'A::f 0 1288490188809,...' is incorrect.
Verified that it works on MontaVista build 3.4.3. Still failing on: armv5tl-montavista-linuxeabi-g++ (GCC) 4.3.0 20071211 (experimental) [trunk revision 130777]
Not sure this should count as a regression, since in 3.4 this was using different ABI. If you compile with -mabi=atpcs which matches 3.4, it will work even in 4.3. Anyway, I think: --- gcc/config/arm/arm.c.jj 2007-12-11 00:23:29.000000000 +0100 +++ gcc/config/arm/arm.c 2007-12-13 15:26:01.000000000 +0100 @@ -17765,14 +17765,20 @@ arm_output_load_gr (rtx *operands) static void arm_setup_incoming_varargs (CUMULATIVE_ARGS *cum, - enum machine_mode mode ATTRIBUTE_UNUSED, - tree type ATTRIBUTE_UNUSED, + enum machine_mode mode, + tree type, int *pretend_size, int second_time ATTRIBUTE_UNUSED) { + int nregs = cum->nregs; + if (nregs & 1 + && ARM_DOUBLEWORD_ALIGN + && arm_needs_doubleword_align (mode, type)) + nregs++; + cfun->machine->uses_anonymous_args = 1; - if (cum->nregs < NUM_ARG_REGS) - *pretend_size = (NUM_ARG_REGS - cum->nregs) * UNITS_PER_WORD; + if (nregs < NUM_ARG_REGS) + *pretend_size = (NUM_ARG_REGS - nregs) * UNITS_PER_WORD; } /* Return nonzero if the CONSUMER instruction (a store) does not need should fix this, let me poke around a little bit some more and add a testcase. I'll need some volunteer to bootstrap/regtest it though, no arms here...
Subject: Bug 34281 Author: jakub Date: Thu Dec 27 08:31:54 2007 New Revision: 131196 URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=131196 Log: PR target/34281 * config/arm/arm.c (arm_setup_incoming_varargs): If last named argument needs double word alignment and cum->nregs is odd, account for the inserted padding. * gcc.c-torture/execute/20071213-1.c: New test. Added: trunk/gcc/testsuite/gcc.c-torture/execute/20071213-1.c Modified: trunk/gcc/ChangeLog trunk/gcc/config/arm/arm.c trunk/gcc/testsuite/ChangeLog
http://gcc.gnu.org/ml/gcc-testresults/2007-12/msg01313.html is with the patch I've just checked in, without the arm.c part there were additional FAILs for the newly added testcase, other than that identical results.