rs6000: Use unspec_volatile for darn (PR91481)

Every call to darn should deliver a *new* random number; such calls
should not be CSEd together.  So they should be unspec_volatile, not
plain unspec.

	PR target/91481
	* config/rs6000/rs6000.md (unspec): Delete UNSPEC_DARN, UNSPEC_DARN_32,
	and UNSPEC_DARN_RAW.
	(unspecv): New enumerator values UNSPECV_DARN, UNSPECV_DARN_32, and
	UNSPECV_DARN_RAW.
	(darn_32): Use an unspec_volatile, and UNSPECV_DARN_32.
	(darn_raw): Use an unspec_volatile, and UNSPECV_DARN_RAW.
	(darn): Use an unspec_volatile, and UNSPECV_DARN.

From-SVN: r274835

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index a9e5668343ff5af14248d987f0ad2370c96ec4d0..3ef76cefb8606b3a1ce65adc72fc95b68006eb68 100644 (file)
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,14 @@
+2019-08-22  Segher Boessenkool  <segher@kernel.crashing.org>
+
+       PR target/91481
+       * config/rs6000/rs6000.md (unspec): Delete UNSPEC_DARN, UNSPEC_DARN_32,
+       and UNSPEC_DARN_RAW.
+       (unspecv): New enumerator values UNSPECV_DARN, UNSPECV_DARN_32, and
+       UNSPECV_DARN_RAW.
+       (darn_32): Use an unspec_volatile, and UNSPECV_DARN_32.
+       (darn_raw): Use an unspec_volatile, and UNSPECV_DARN_RAW.
+       (darn): Use an unspec_volatile, and UNSPECV_DARN.
+
 2019-08-22  Segher Boessenkool  <segher@kernel.crashing.org>
 
        * config/rs6000/altivec.md (unspec): Delete UNSPEC_DARN, UNSPEC_DARN_32,

diff --git a/gcc/config/rs6000/rs6000.md b/gcc/config/rs6000/rs6000.md
index 68cdf6817c291541fd77d783076e010825192e4c..b0aea2329687d8ac4f2177d27b4a3aacefd2f9b8 100644 (file)
--- a/gcc/config/rs6000/rs6000.md
+++ b/gcc/config/rs6000/rs6000.md
@@ -134,9 +134,6 @@
    UNSPEC_LSQ
    UNSPEC_FUSION_GPR
    UNSPEC_STACK_CHECK
-   UNSPEC_DARN
-   UNSPEC_DARN_32
-   UNSPEC_DARN_RAW
    UNSPEC_CMPRB
    UNSPEC_CMPRB2
    UNSPEC_CMPEQB
@@ -168,6 +165,9 @@
    UNSPECV_EH_RR               ; eh_reg_restore
    UNSPECV_ISYNC               ; isync instruction
    UNSPECV_MFTB                        ; move from time base
+   UNSPECV_DARN                        ; darn 1 (deliver a random number)
+   UNSPECV_DARN_32             ; darn 2
+   UNSPECV_DARN_RAW            ; darn 0
    UNSPECV_NLGR                        ; non-local goto receiver
    UNSPECV_MFFS                        ; Move from FPSCR
    UNSPECV_MFFSL               ; Move from FPSCR light instruction version
@@ -14387,21 +14387,21 @@
 
 (define_insn "darn_32"
   [(set (match_operand:SI 0 "register_operand" "=r")
-        (unspec:SI [(const_int 0)] UNSPEC_DARN_32))]
+        (unspec_volatile:SI [(const_int 0)] UNSPECV_DARN_32))]
   "TARGET_P9_MISC"
   "darn %0,0"
   [(set_attr "type" "integer")])
 
 (define_insn "darn_raw"
   [(set (match_operand:DI 0 "register_operand" "=r")
-        (unspec:DI [(const_int 0)] UNSPEC_DARN_RAW))]
+        (unspec_volatile:DI [(const_int 0)] UNSPECV_DARN_RAW))]
   "TARGET_P9_MISC && TARGET_64BIT"
   "darn %0,2"
   [(set_attr "type" "integer")])
 
 (define_insn "darn"
   [(set (match_operand:DI 0 "register_operand" "=r")
-        (unspec:DI [(const_int 0)] UNSPEC_DARN))]
+        (unspec_volatile:DI [(const_int 0)] UNSPECV_DARN))]
   "TARGET_P9_MISC && TARGET_64BIT"
   "darn %0,1"
   [(set_attr "type" "integer")])