[PATCH] rs6000: Fix PR63195

Segher Boessenkool segher@kernel.crashing.org
Mon Sep 8 22:42:00 GMT 2014

When reload decides it needs to reload something that was assigned a
register before it will only look at the contraint, not the predicate.
This means that for the *bool<mode>3 I added with predicate logical_operand
(that is registers, and unsigned numbers that have only the low 16 or next
16 bits set) and contraint "r,n" it will put any integer constant in "n".
That won't work.  This patch splits the pattern in two, one for "r", one
for "n", solving the problem.  This is not a pessimisation because constant
propagation should already have taken care of any constants we *can* handle.

Also, this situation happens very rarely: nothing in the testsuite triggers
it, and a normal bootstrap doesn't either, but --enable-checking=release
did.  It seems it doesn't happen at all with LRA, or even more rarely.

Bootstrapped and tested on powerpc64-linux, m64,m32,m32/mpowerpc64,m64/mlra,
no regressions.  Also tested with --enable-checking=release, and that now
again bootstraps.

Okay for mainline?


2014-09-08  Segher Boessenkool  <segher@kernel.crashing.org>

	PR target/63195
	* config/rs6000/rs6000.md (*bool<mode>3): Allow only register
	operands.  Split off the constant operand alternative to ...
	(*bool<mode>3_imm): New.

 gcc/config/rs6000/rs6000.md | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 2df8e41..b5aeaed 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -2996,14 +2996,21 @@ (define_expand "xor<mode>3"
 (define_insn "*bool<mode>3"
-  [(set (match_operand:GPR 0 "gpc_reg_operand" "=r,r")
+  [(set (match_operand:GPR 0 "gpc_reg_operand" "=r")
 	(match_operator:GPR 3 "boolean_or_operator"
-	 [(match_operand:GPR 1 "gpc_reg_operand" "%r,r")
-	  (match_operand:GPR 2 "logical_operand" "r,n")]))]
+	 [(match_operand:GPR 1 "gpc_reg_operand" "r")
+	  (match_operand:GPR 2 "gpc_reg_operand" "r")]))]
-  "@
-   %q3 %0,%1,%2
-   %q3i%e2 %0,%1,%u2"
+  "%q3 %0,%1,%2"
+  [(set_attr "type" "logical")])
+(define_insn "*bool<mode>3_imm"
+  [(set (match_operand:GPR 0 "gpc_reg_operand" "=r")
+	(match_operator:GPR 3 "boolean_or_operator"
+	 [(match_operand:GPR 1 "gpc_reg_operand" "%r")
+	  (match_operand:GPR 2 "logical_const_operand" "n")]))]
+  ""
+  "%q3i%e2 %0,%1,%u2"
   [(set_attr "type" "logical")])
 (define_insn_and_split "*bool<mode>3_dot"

More information about the Gcc-patches mailing list