[cris-decc0,1/14] cris: Emit trivial btstq expected by gcc.target/cris/sync-2i.c, sync-2c.c
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Message ID 202002120648.01C6mEqB026246@ignucius.se.axis.com
State New
Headers show
Series
  • A set of compare-elimination-fixes.
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Commit Message

Hans-Peter Nilsson Feb. 12, 2020, 6:48 a.m. UTC
PR target/93372
* config/cris/cris.md (zcond): New code_iterator.
("*cbranch<mode>4_btstq<CC>"): New insn_and_split.

As the added FIXME says, the new insn_and_split generates only a
small subset of the bit-tests that can be matched by "*btst" and
that were emitted by the undecc0rated cris.md at combine-time,
but it's naturally separable from a general variant by being
just what's needed for the test-cases that were previously
xfailed, and that no additional CCmodes are required.
---
 gcc/config/cris/cris.md | 27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

Patch
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diff --git a/gcc/config/cris/cris.md b/gcc/config/cris/cris.md
index 7690d7f06..0b42197a9 100644
--- a/gcc/config/cris/cris.md
+++ b/gcc/config/cris/cris.md
@@ -178,6 +178,7 @@  (define_code_iterator shiftrt [ashiftrt lshiftrt])
 (define_code_attr shlr [(ashiftrt "ashr") (lshiftrt "lshr") (ashift "ashl")])
 (define_code_attr slr [(ashiftrt "asr") (lshiftrt "lsr") (ashift "lsl")])
 
+(define_code_iterator zcond [eq ne])
 (define_code_iterator ncond [eq ne gtu ltu geu leu])
 (define_code_iterator ocond [gt le])
 (define_code_iterator rcond [lt ge])
@@ -1934,6 +1935,32 @@  (define_insn_and_split "*cbranch<mode>4"
 		      (pc)))]
   "")
 
+;; FIXME: this matches only a subset of what the "*btst" pattern can handle.
+(define_insn_and_split "*cbranch<mode>4_btstq<CC>"
+  [(set (pc)
+	(if_then_else
+	 (zcond
+	  (zero_extract:BWD
+	   (match_operand:BWD 0 "register_operand" "r")
+	   (match_operand 1 "const_int_operand" "Kc")
+	   (const_int 0))
+	  (const_int 0))
+	 (label_ref (match_operand 2 ""))
+	 (pc)))
+   (clobber (reg:CC CRIS_CC0_REGNUM))]
+  ""
+  "#"
+  "&& reload_completed"
+  [(set (reg:CC CRIS_CC0_REGNUM)
+	(compare:CC
+	 (zero_extract:SI (match_dup 0) (match_dup 1) (const_int 0))
+	 (const_int 0)))
+   (set (pc)
+	(if_then_else (zcond (reg:CC CRIS_CC0_REGNUM) (const_int 0))
+		      (label_ref (match_dup 3))
+		      (pc)))]
+  "")
+
 
 ;; We suffer from the same overflow-bit-gets-in-the-way problem as
 ;; e.g. m68k, so we have to check if overflow bit is set on all "signed"