[PowerPC][HTM] Fix impossible reg-to-reg copy assert with ttest builtin

Summary:
This is exposed by our internal testing.
The reduced testcase will assert with "Impossible reg-to-reg copy"

We can't use COPY to do 32-bit to 64-bit conversion.

Reviewers: kbarton, hfinkel, nemanjai

Reviewed By: hfinkel

Subscribers: hiraditya, MaskRay, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D64499

llvm-svn: 366255

llvm/lib/Target/PowerPC/PPCInstrHTM.td

@@ -164,6 +164,8 @@ def : Pat<(int_ppc_tsuspend),
           (TSR 0)>;
 
 def : Pat<(i64 (int_ppc_ttest)),
-          (RLDICL (i64 (COPY (TABORTWCI 0, (LI 0), 0))), 36, 28)>;
+          (RLDICL (i64 (INSERT_SUBREG (i64 (IMPLICIT_DEF)),
+                                      (TABORTWCI 0, (LI 0), 0), sub_32)),
+                   36, 28)>;
 
 } // [HasHTM]

llvm/test/CodeGen/PowerPC/htm-ttest.ll

@@ -0,0 +1,30 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py
+; RUN: llc -mtriple=powerpc64le-unknown-linux-gnu -verify-machineinstrs \
+; RUN:     -mcpu=pwr8 -mattr=+htm < %s | FileCheck %s
+
+define dso_local void @main() #0 {
+; CHECK-LABEL: main:
+; CHECK:       # %bb.0:
+; CHECK-NEXT:    li 3, 0
+; CHECK-NEXT:    tabortwci. 0, 3, 0
+; CHECK-NEXT:    mfocrf 3, 128
+; CHECK-NEXT:    rldicl 3, 3, 36, 28
+; CHECK-NEXT:    rlwinm. 3, 3, 31, 30, 31
+; CHECK-NEXT:    beqlr+ 0
+; CHECK-NEXT:  # %bb.1:
+  %1 = call i64 @llvm.ppc.ttest() #1
+  %2 = lshr i64 %1, 1
+  %3 = and i64 %2, 3
+  %4 = icmp eq i64 %3, 0
+  br i1 %4, label %5, label %6
+
+5:                                                ; preds = %0
+  ret void
+
+6:                                                ; preds = %0
+  unreachable
+}
+
+; Function Attrs: nounwind
+declare i64 @llvm.ppc.ttest() #1
+