https://gcc.gnu.org/g:8a9490979b97d6ce3498fde891b04597a48925ed
commit r16-7515-g8a9490979b97d6ce3498fde891b04597a48925ed Author: Kalvis Duckmanton <[email protected]> Date: Sat Feb 14 15:10:15 2026 +0000 VAX: Fix ICE in fixup_reorder_chain when building gimple_match.cc [PR112400] When cross-compiling itself for VAX, GCC terminates abruptly with an ICE when compiling gimple_match.cc; the root cause seems to be an incompletely removed computed jump instruction, which causes the assertion in cfgrtl.cc around line 4083, to no longer hold. I have verified that the problem is present in GCC 15.2.0 and believe that it's also present in trunk (based on the fact that the patterns for the "casesi1" and "*casesi1" instructions in 15.2.0 and trunk are the same). To fix this issue wrap the limit operand in a USE, to allow `single_set' to identify it as an RTL expression setting PC. This allows the optimizer to optimize away case statements branching only to a basic block, removing the ICE. Include a test case reduced from gimple_match.cc, which demonstrates the problem in GCC 15.2.0 on NetBSD/amd64 cross-compiling for VAX. gcc/ PR target/112400 * config/vax/vax.md (casesi1): Wrap naked operand 1 with a USE where used with the insn split to. (*casesi1): Likewise naked incoming operand 1. gcc/testsuite/ PR target/112400 * g++.dg/torture/pr112400.C: New file. Diff: --- gcc/config/vax/vax.md | 4 +- gcc/testsuite/g++.dg/torture/pr112400.C | 114 ++++++++++++++++++++++++++++++++ 2 files changed, 116 insertions(+), 2 deletions(-) diff --git a/gcc/config/vax/vax.md b/gcc/config/vax/vax.md index 9eb831c49f8d..71345e4c3ea3 100644 --- a/gcc/config/vax/vax.md +++ b/gcc/config/vax/vax.md @@ -2909,7 +2909,7 @@ "#" "reload_completed" [(parallel - [(match_dup 1) + [(use (match_dup 1)) (set (pc) (plus:SI (sign_extend:SI (mem:HI (plus:SI @@ -2922,7 +2922,7 @@ "") (define_insn "*casesi1" - [(match_operand:SI 1 "const_int_operand" "n") + [(use (match_operand:SI 1 "const_int_operand" "n")) (set (pc) (plus:SI (sign_extend:SI (mem:HI (plus:SI diff --git a/gcc/testsuite/g++.dg/torture/pr112400.C b/gcc/testsuite/g++.dg/torture/pr112400.C new file mode 100644 index 000000000000..b703c80ce73d --- /dev/null +++ b/gcc/testsuite/g++.dg/torture/pr112400.C @@ -0,0 +1,114 @@ +/* { dg-do compile } */ +/* { dg-options "-Wno-return-type" } */ + +typedef struct a *b; +template <typename c, typename d> c e(d); +enum f { g, h, i }; +enum j { k, l, m, aa }; +struct a { + f ab; +}; +struct af { +} n; +struct ah; +class al; +b q; +void r(a *); +struct o : af {}; +struct p : o {}; +struct ag : p {}; +j s(af *); +b t(); +f fn4(); +unsigned fn5(ag *); +b u(ag *, unsigned); +af *v(b(b), b); +static bool w(al *, af *, b(b), b aw, b *ax, j) { + r(ax[2]); + if (aw) + return false; +} +ag *ay; +void x(al *at, b as(b), b bb, b bc) { + switch (bb->ab) + case i: + if (af *bd = v(as, bb)) + if (e<ah *>(bd)) + switch (fn4()) + case h: { + b be; + switch (be->ab) + case i: + if (af *bf = v(as, be)) + if (e<ah *>(bf)) + if (ag *bg = e<ag *>(bf)) + switch (s(bg)) { + case k: + if (fn5(bg) == 1) { + b bh = u(bg, 0); + bh = t(); + switch (bc->ab) + case g: { + b ax[]{be, bh, bc}; + w(at, &n, as, q, ax, k); + } + } + break; + case l: + if (fn5(bg) == 1) { + b bh = u(bg, 0); + bh = t(); + switch (bc->ab) + case g: { + b ax[]{be, bh, bc}; + w(at, &n, as, q, ax, l); + } + } + } + } + else switch (s(ay)) { + case k: + if (fn5(ay) == 1) { + b be = u(ay, 0); + be = t(); + switch (bc->ab) + case g: { + b ax[]{bb, be, bc}; + w(at, &n, as, q, ax, k); + } + } + break; + case l: + if (fn5(ay) == 1) { + b be = u(ay, 0); + be = t(); + switch (bc->ab) + case g: { + b ax[]{bb, be, bc}; + w(at, &n, as, q, ax, l); + } + } + break; + case m: + if (fn5(ay) == 1) { + b be = u(ay, 0); + be = t(); + switch (bc->ab) + case g: { + b ax[]{bb, be, bc}; + w(at, &n, as, q, ax, m); + } + } + break; + case aa: + if (fn5(ay) == 1) { + b be = u(ay, 0); + be = t(); + switch (bc->ab) + case g: { + b ax[]{bb, be, bc}; + w(at, &n, as, q, ax, aa); + } + } + } +}
