[PATCH, i386]: Fix PR55929, unable to generate reloads for xbegin insn
Uros Bizjak
ubizjak@gmail.com
Thu Jan 10 19:48:00 GMT 2013
Hello!
As mentioned by Andrew is PR, reload can't handle jump_insns. Expand
with %eax hard register temporary to avoid this limitation.
2012-01-10 Uros Bizjak <ubizjak@gmail.com>
PR target/55929
* config/i386/i386.md (xbegin): Use %eax as a temporary register.
Bootstrapped and regression tested on x86_64-pc-linux-gnu {,-m32} and
by compiling libitm/beginend.cc preprocessed source with -Os mrtm
-std=gnu++0x. Committed to mainline SVN.
Uros.
-------------- next part --------------
Index: config/i386/i386.md
===================================================================
--- config/i386/i386.md (revision 195091)
+++ config/i386/i386.md (working copy)
@@ -18013,19 +18013,22 @@
(define_expand "xbegin"
[(set (match_operand:SI 0 "register_operand")
- (unspec_volatile:SI [(match_dup 1)] UNSPECV_XBEGIN))]
+ (unspec_volatile:SI [(const_int 0)] UNSPECV_XBEGIN))]
"TARGET_RTM"
{
rtx label = gen_label_rtx ();
- operands[1] = force_reg (SImode, constm1_rtx);
+ /* xbegin is emitted as jump_insn, so reload won't be able
+ to reload its operand. Force the value into AX hard register. */
+ rtx ax_reg = gen_rtx_REG (SImode, AX_REG);
+ emit_move_insn (ax_reg, constm1_rtx);
- emit_jump_insn (gen_xbegin_1 (operands[1], label));
+ emit_jump_insn (gen_xbegin_1 (ax_reg, label));
emit_label (label);
LABEL_NUSES (label) = 1;
- emit_move_insn (operands[0], operands[1]);
+ emit_move_insn (operands[0], ax_reg);
DONE;
})
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