| Message ID | alpine.BSF.2.02.1211302158360.57912@dair.pair.com |
|---|---|
| State | New |
| Headers | show |
> Of course this matters only to >64bit (i.e. >registersize) values like > TImode, alias __int128. The problem here is that group-loading a > constant for a function return-value doesn't work; it's passed to > simplify_gen_subreg which horks on the VOIDmode constant. Thankfully, > the code below the context handles this case, twice the register-mode, > just fine, so let's just gate the simplify_gen_subreg call with a test > for a VOIDmode source. IMO that's not as clear a cut as it seems. simplify_gen_subreg is supposed to work on VOIDmode constants, at least to be callable on them, because there is the simplify_gen_subreg -> simplify_subreg -> simplify_immed_subreg path.
Index: gcc/expr.c =================================================================== --- gcc/expr.c (revision 192677) +++ gcc/expr.c (working copy) @@ -1739,7 +1739,9 @@ emit_group_load_1 (rtx *tmps, rtx dst, r emit_move_insn (mem, src); tmps[i] = adjust_address (mem, mode, (int) bytepos); } - else if (CONSTANT_P (src) && GET_MODE (dst) != BLKmode + else if (CONSTANT_P (src) + && GET_MODE (src) != VOIDmode + && GET_MODE (dst) != BLKmode && XVECLEN (dst, 0) > 1) tmps[i] = simplify_gen_subreg (mode, src, GET_MODE(dst), bytepos); else if (CONSTANT_P (src))
(No cans of worms opened here, I believe...) For MMIX with the default, Knuth's ABI (returning values in register $0, through the register stack), function return values are prepared in a register-swapped fashion due to the way the register stack works, which has to be expressed as: (parallel [ (expr_list:REG_DEP_TRUE (reg:DI 0 $0) (const_int 8 [0x8])) (expr_list:REG_DEP_TRUE (reg:DI 1 $1) (const_int 0 [0])) ]) i.e. a group load. Compare to the more intuitive "GNU ABI", passing parameters straightforwardly, with the order in the called and the calling function being the same, starting with global register $231. Of course this matters only to >64bit (i.e. >registersize) values like TImode, alias __int128. The problem here is that group-loading a constant for a function return-value doesn't work; it's passed to simplify_gen_subreg which horks on the VOIDmode constant. Thankfully, the code below the context handles this case, twice the register-mode, just fine, so let's just gate the simplify_gen_subreg call with a test for a VOIDmode source. Bootstrapped and checked for x86_64-*-linux-gnu and checked for mmix-knuth-mmixware, both -mabi=gnu multilib (no regressions) and the base multilib with the Knuth ABI, where the patch below fixes: Running /home/hp/gcctop/tmp/mbasf/gcc/gcc/testsuite/gcc.c-torture/execute/execute.exp ... ... FAIL: gcc.c-torture/execute/pr54471.c compilation, -O1 (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O2 (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O3 -fomit-frame-pointer (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O3 -fomit-frame-pointer -funroll-loops (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O3 -g (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -Os (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O2 -flto -fno-use-linker-plugin -flto-partition=none (internal compiler error) FAIL: gcc.c-torture/execute/pr54471.c compilation, -O2 -flto -fuse-linker-plugin -fno-fat-lto-objects (internal compiler error) ... Running /home/hp/gcctop/tmp/mbasf/gcc/gcc/testsuite/gcc.dg/dg.exp ... ... FAIL: gcc.dg/pr32912-2.c (internal compiler error) FAIL: gcc.dg/pr32912-2.c (test for excess errors) FAIL: gcc.dg/pr32912-3.c (internal compiler error) FAIL: gcc.dg/pr32912-3.c (test for excess errors) ... Running /home/hp/gcctop/tmp/mbasf/gcc/gcc/testsuite/gcc.dg/torture/dg-torture.exp ... ... FAIL: c-c++-common/torture/vector-compare-2.c -O1 (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O1 (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -O2 (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O2 (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -fomit-frame-pointer (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -fomit-frame-pointer (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -fomit-frame-pointer -funroll-loops (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -fomit-frame-pointer -funroll-loops (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -fomit-frame-pointer -funroll-all-loops -finline-functions (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -g (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O3 -g (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -Os (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -Os (test for excess errors) FAIL: c-c++-common/torture/vector-compare-2.c -O2 -flto -fno-use-linker-plugin -flto-partition=none (internal compiler error) FAIL: c-c++-common/torture/vector-compare-2.c -O2 -flto -fno-use-linker-plugin -flto-partition=none (test for excess errors) (ditto the c++ testsuite for c-c++-common/torture/vector-compare-2.c) (FWIW, the failing gcc.dg/pr32912-3.c is a regression.) Ok? gcc: * expr.c (emit_group_load_1): Don't call simplify_gen_subreg for a VOIDmode src. brgds, H-P