[Bug target/59379] [4.9 Regression] gomp_init_num_threads is compiled into an infinite loop with --with-arch=corei7 --with-cpu=slm
hjl.tools at gmail dot com
gcc-bugzilla@gcc.gnu.org
Sat Jan 18 17:13:00 GMT 2014
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=59379
H.J. Lu <hjl.tools at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |ubizjak at gmail dot com
--- Comment #15 from H.J. Lu <hjl.tools at gmail dot com> ---
The problem is in ix86_split_lea_for_addr. For LEA operation with
SImode_address_operand, which zero-extends SImode to DImode, it turns
(set (reg:DI) ...)
into
(set (reg:SI) ...)
We need to do
(set (reg:DI) (zero_extend:DI (reg:SI)))
at the end:
---
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index ff210c8..5ceccdf 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -18375,7 +18375,7 @@ ix86_split_lea_for_addr (rtx insn, rtx operands[], enum
machine_mode mode)
ix86_emit_binop (PLUS, mode, target, parts.disp);
ix86_emit_binop (PLUS, mode, target, tmp1);
- return;
+ goto check_mode;
}
ix86_emit_binop (PLUS, mode, target, tmp);
@@ -18384,6 +18384,13 @@ ix86_split_lea_for_addr (rtx insn, rtx operands[],
enum machine_mode mode)
if (parts.disp && parts.disp != const0_rtx)
ix86_emit_binop (PLUS, mode, target, parts.disp);
}
+
+check_mode:
+ if (mode != GET_MODE (operands[0]))
+ {
+ gcc_assert (mode == SImode && GET_MODE (operands[0]) == DImode);
+ emit_insn (gen_zero_extendsidi2 (operands[0], target));
+ }
}
/* Return true if it is ok to optimize an ADD operation to LEA
---
Or we can avoid splitting LEA for SImode_address_operand by
---
diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md
index 954bbed..e5e6e12 100644
--- a/gcc/config/i386/i386.md
+++ b/gcc/config/i386/i386.md
@@ -5415,10 +5415,11 @@
else
return "lea{<imodesuffix>}\t{%E1, %0|%0, %E1}";
}
- "reload_completed && ix86_avoid_lea_for_addr (insn, operands)"
+ "reload_completed
+ && !SImode_address_operand (operands[1], VOIDmode)
+ && ix86_avoid_lea_for_addr (insn, operands)"
[(const_int 0)]
{
- enum machine_mode mode = <MODE>mode;
rtx pat;
/* ix86_avoid_lea_for_addr re-recognizes insn and may
@@ -5428,12 +5429,7 @@
operands[0] = SET_DEST (pat);
operands[1] = SET_SRC (pat);
- /* Emit all operations in SImode for zero-extended addresses. Recall
- that x86_64 inheretly zero-extends SImode operations to DImode. */
- if (SImode_address_operand (operands[1], VOIDmode))
- mode = SImode;
-
- ix86_split_lea_for_addr (curr_insn, operands, mode);
+ ix86_split_lea_for_addr (curr_insn, operands, <MODE>mode);
DONE;
}
[(set_attr "type" "lea")
---
Either patch fixes the problem.
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