[PowerPC] Support the (old) cntlz instruction alias

Some old assembly code uses the cntlz alias for cntlzw, binutils supports this,
and we should too. Fixes PR22519.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@228719 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCInstrInfo.td b/lib/Target/PowerPC/PPCInstrInfo.td
index 36f7f5a2462f1f2905a769deee327fef8361dfb2..f6cc93dcf26a11e51b323dab822c7d537221e2d1 100644 (file)
--- a/lib/Target/PowerPC/PPCInstrInfo.td
+++ b/lib/Target/PowerPC/PPCInstrInfo.td
@@ -3566,6 +3566,9 @@ def : InstAlias<"rotlw. $rA, $rS, $rB", (RLWNMo gprc:$rA, gprc:$rS, gprc:$rB, 0,
 def : InstAlias<"clrlwi $rA, $rS, $n", (RLWINM gprc:$rA, gprc:$rS, 0, u5imm:$n, 31)>;
 def : InstAlias<"clrlwi. $rA, $rS, $n", (RLWINMo gprc:$rA, gprc:$rS, 0, u5imm:$n, 31)>;
 
+def : InstAlias<"cntlz $rA, $rS", (CNTLZW gprc:$rA, gprc:$rS)>;
+def : InstAlias<"cntlz. $rA, $rS", (CNTLZWo gprc:$rA, gprc:$rS)>;
+
 def EXTLDI : PPCAsmPseudo<"extldi $rA, $rS, $n, $b",
                           (ins g8rc:$rA, g8rc:$rS, u6imm:$n, u6imm:$b)>;
 def EXTLDIo : PPCAsmPseudo<"extldi. $rA, $rS, $n, $b",

diff --git a/test/MC/PowerPC/ppc64-encoding.s b/test/MC/PowerPC/ppc64-encoding.s
index 6d09dfd8e5fc5ccfe51344fe362de855586dbd11..d2ac6692e713b48a1deac78b7f556c7cdce65d66 100644 (file)
--- a/test/MC/PowerPC/ppc64-encoding.s
+++ b/test/MC/PowerPC/ppc64-encoding.s
@@ -612,6 +612,12 @@
 # CHECK-BE: cntlzw. 2, 3                    # encoding: [0x7c,0x62,0x00,0x35]
 # CHECK-LE: cntlzw. 2, 3                    # encoding: [0x35,0x00,0x62,0x7c]
             cntlzw. 2, 3
+# CHECK-BE: cntlzw 2, 3                     # encoding: [0x7c,0x62,0x00,0x34]
+# CHECK-LE: cntlzw 2, 3                     # encoding: [0x34,0x00,0x62,0x7c]
+            cntlz  2, 3
+# CHECK-BE: cntlzw. 2, 3                    # encoding: [0x7c,0x62,0x00,0x35]
+# CHECK-LE: cntlzw. 2, 3                    # encoding: [0x35,0x00,0x62,0x7c]
+            cntlz.  2, 3
             cmpb 7, 21, 4
 # CHECK-BE: cmpb 7, 21, 4                   # encoding: [0x7e,0xa7,0x23,0xf8]
 # CHECK-LE: cmpb 7, 21, 4                   # encoding: [0xf8,0x23,0xa7,0x7e]