ARM peephole2 from 2003 never merged, still valid

[Fredrik Hederstierna <fredrik.hederstierna@verisure.com>]

I found this patch from 2003 by Tamas Gergely that was never merged.


Though it seems to still be valid, since when applying it, the CSiBE benchmark reduce total code size -170 bytes, making 35 out of 893 files smaller (from -4 to -12 bytes (1-3 instructions).


Bug


asd


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updated patch:


diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 20bdc2bec37..4c924499ad9 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-06-01  Fredrik Hederstierna  <fredrik@hederstierna.com>
+            Tamas Gergely <gertom@rgai.hu>
+
+       * gcc/config/arm/arm.md: new peephole2 pattern added for extending
+       move and compare parallelization. Retake from 2003 patch adapted.
+
 2019-06-01  Martin Sebor  <msebor@redhat.com>

        PR middle-end/90694
diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index ae582172ab9..753d18fbfc5 100644
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -10951,6 +10951,19 @@
   ""
 )

+; The same as the previous, but with exchanged operands
+;
+(define_peephole2
+  [(set (match_operand:SI 0 "arm_general_register_operand" "")
+       (match_operand:SI 1 "arm_general_register_operand" ""))
+   (set (reg:CC CC_REGNUM)
+       (compare:CC (match_dup 0) (const_int 0)))]
+  "TARGET_ARM"
+  [(parallel [(set (reg:CC CC_REGNUM) (compare:CC (match_dup 1) (const_int 0)))
+             (set (match_dup 0) (match_dup 1))])]
+  ""
+)
+
 (define_split
   [(set (match_operand:SI 0 "s_register_operand" "")
        (and:SI (ge:SI (match_operand:SI 1 "s_register_operand" "")