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authorJeff Law <jlaw@ventanamicro.com>2022-11-16 18:47:59 -0700
committerJeff Law <jlaw@ventanamicro.com>2022-11-16 18:47:59 -0700
commite214cab68cb34e77622b91113f7698cf137bbdd6 (patch)
tree4ec713f43436ea47beb20fb2df10140edeb9050d
parentf69a8299c1d95548e1539227fb7b8f5581aeb29b (diff)
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Fix multiple recent sh3/sh3eb regressions
So my tester started showing even more regressions on the sh3/sh4 runs recently (beyond the one recently reported in BZ triggered by some DCE related changes). Bisection kept showing inconsistent results. I was starting to think memory management error, but valgrind didn't flag anything. After a bit of head-banging I was able to track it down to predicate tests called from the SH specific combiner passes. And once I started getting inside the actual code for the predicate function it became pretty obvious. The predicate routines are supposed to return a bool, fine and they dutifully set the low bit in %eax properly. The *caller* was looking at the full register. Uh-oh. Naturally we became dependent on what happened to be in the upper 31 bits of a register. That's why the bug would come and go so willy-nilly. This was ultimately chased down to an incorrect prototype in sh_treg_combine.cc for predicate functions defined via define_predicate. Removing the bogus prototypes and instead including the generated tm-preds.h fixes this problem. I also checked the other ports for similar problems (specifically looking for a extern int.*_operand, then for each of the hits looking to see if the predicate was defined via define_predicate). No other ports had similar braindamage. This fixes the most recent regressions in my tester for sh3/sh3eb and I strongly suspect sh4. It does not fix 107704, but I think Richi and I both agree that's a visitation order issue and we were just getting lucky before. gcc/ * config/sh/sh_treg_combine.cc: Include tm-preds.h. (t_reg_operand): Remove bogus prototype. (negt_reg_operand): Likewise.
-rw-r--r--gcc/config/sh/sh_treg_combine.cc5
1 files changed, 1 insertions, 4 deletions
diff --git a/gcc/config/sh/sh_treg_combine.cc b/gcc/config/sh/sh_treg_combine.cc
index f6553c0..ab7dc5d 100644
--- a/gcc/config/sh/sh_treg_combine.cc
+++ b/gcc/config/sh/sh_treg_combine.cc
@@ -37,6 +37,7 @@ along with GCC; see the file COPYING3. If not see
#include "cfgrtl.h"
#include "tree-pass.h"
#include "expr.h"
+#include "tm-preds.h"
/*
This pass tries to optimize for example this:
@@ -426,10 +427,6 @@ is_conditional_insn (rtx_insn* i)
return GET_CODE (p) == SET && GET_CODE (XEXP (p, 1)) == IF_THEN_ELSE;
}
-// FIXME: Remove dependency on SH predicate function somehow.
-extern int t_reg_operand (rtx, machine_mode);
-extern int negt_reg_operand (rtx, machine_mode);
-
// - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - - -
// RTL pass class