On Tue, Aug 25, 2015 at 10:08:54AM -0700, Segher Boessenkool wrote:
> -(define_insn_and_split "*and<mode>3_imm_dot_shifted"
> - [(set (match_operand:CC 3 "cc_reg_operand" "=x,?y")
> +(define_insn "*and<mode>3_imm_dot_shifted"
> + [(set (match_operand:CC 3 "cc_reg_operand" "=x")
Is this really the best solution? The operand predicate allows any
cr, but the constraint only cr0. In the past we've seen this sort of
thing result in "insn does not satisfy its constraints" errors, and if
the operand is successfully reloaded you'll get slow mcrf insns. At
-O1 the testcase generates:
andi. 8,3,0x16
mcrf 4,0
I started throwing together a patch yesterday, before you claimed the
bug. With this patch, I see what looks to be better code despite it
being larger:
li 9,22
and 9,3,9
cmpdi 4,9,0
diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 87abd6e..a9eea80 100644
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -3060,17 +3060,18 @@
return "#";
}
"&& reload_completed && cc_reg_not_cr0_operand (operands[3], CCmode)"
- [(set (match_dup 0)
- (and:GPR (lshiftrt:GPR (match_dup 1)
- (match_dup 4))
- (match_dup 2)))
+ [(set (match_dup 0) (match_dup 2))
+ (set (match_dup 0) (and:GPR (match_dup 1) (match_dup 0)))
(set (match_dup 3)
(compare:CC (match_dup 0)
(const_int 0)))]
- ""
+ "
+{
+ operands[2] = GEN_INT (UINTVAL (operands[2]) << INTVAL (operands[4]));
+}"
[(set_attr "type" "logical")
(set_attr "dot" "yes")
- (set_attr "length" "4,8")])
+ (set_attr "length" "4,12")])
(define_insn "and<mode>3_mask"
--
Alan Modra
Australia Development Lab, IBM
