[PowerPC] Implement the isSelectSupported() target hook

Summary:
PowerPC has scalar selects (isel) and vector mask selects (xxsel). But PowerPC
does not have vector CR selects, PowerPC does not support scalar condition
selects on vectors.
In addition to implementing this hook, isSelectSupported() should return false
when the SelectSupportKind is ScalarCondVectorVal, so that predictable selects
are converted into branch sequences.

Reviewed By: steven.zhang,  hfinkel

Differential Revision: https://reviews.llvm.org/D55754

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@349727 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Target/PowerPC/PPCISelLowering.h b/lib/Target/PowerPC/PPCISelLowering.h
index 09039cb77363d909561ccea7d3c6098d5c5e7d94..30acd60eba6f4c6c245cf0d1c2e6000a4c8a9314 100644 (file)
--- a/lib/Target/PowerPC/PPCISelLowering.h
+++ b/lib/Target/PowerPC/PPCISelLowering.h
@@ -576,6 +576,11 @@ namespace llvm {
     /// DAG node.
     const char *getTargetNodeName(unsigned Opcode) const override;
 
+    bool isSelectSupported(SelectSupportKind Kind) const override {
+      // PowerPC does not support scalar condition selects on vectors.
+      return (Kind != SelectSupportKind::ScalarCondVectorVal);
+    }
+
     /// getPreferredVectorAction - The code we generate when vector types are
     /// legalized by promoting the integer element type is often much worse
     /// than code we generate if we widen the type for applicable vector types.

diff --git a/test/CodeGen/PowerPC/select-i1-vs-i1.ll b/test/CodeGen/PowerPC/select-i1-vs-i1.ll
index a2df1828afc8965da0929ce1a6992dfefb8e88a2..51bd26d6828cc594461605ade46b8fe0a8635241 100644 (file)
--- a/test/CodeGen/PowerPC/select-i1-vs-i1.ll
+++ b/test/CodeGen/PowerPC/select-i1-vs-i1.ll
@@ -928,10 +928,8 @@ entry:
 ; CHECK-LABEL: @testv4floateq
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 3, 4
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 1, 2
-; CHECK: crxor [[REG1:[0-9]+]], {{[0-9]+}}, {{[0-9]+}}
-; CHECK: bc 12, [[REG1]], .LBB[[BB1:[0-9_]+]]
-; CHECK: vmr 3, 2
-; CHECK: .LBB[[BB1]]
+; CHECK: creqv [[REG1:[0-9]+]], {{[0-9]+}}, {{[0-9]+}}
+; CHECK: bclr 12, [[REG1]], 0
 ; CHECK: vmr 2, 3
 ; CHECK: blr
 }
@@ -1065,7 +1063,7 @@ entry:
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 3, 4
 ; CHECK: bc 12, 2, .LBB[[BB:[0-9_]+]]
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 1, 2
-; CHECK: bc 4, 2, .LBB[[BB]]
+; CHECK: bclr 12, 2, 0
 ; CHECK: .LBB[[BB]]:
 ; CHECK: vmr 2, 3
 ; CHECK: blr
@@ -1083,7 +1081,7 @@ entry:
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 3, 4
 ; CHECK: bc 4, 2, .LBB[[BB:[0-9_]+]]
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 1, 2
-; CHECK: bc 12, 2, .LBB[[BB]]
+; CHECK: bclr 4, 2, 0
 ; CHECK: .LBB[[BB]]:
 ; CHECK: vmr 2, 3
 ; CHECK: blr
@@ -1134,10 +1132,8 @@ entry:
 ; CHECK-LABEL: @testv2doubleeq
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 3, 4
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 1, 2
-; CHECK: crxor [[REG1:[0-9]+]], {{[0-9]+}}, {{[0-9]+}}
-; CHECK: bc 12, [[REG1]], .LBB[[BB55:[0-9_]+]]
-; CHECK: vmr 3, 2
-; CHECK: .LBB[[BB55]]
+; CHECK: creqv [[REG1:[0-9]+]], {{[0-9]+}}, {{[0-9]+}}
+; CHECK: bclr 12, [[REG1]], 0
 ; CHECK: vmr 2, 3
 ; CHECK: blr
 }
@@ -1188,7 +1184,7 @@ entry:
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 3, 4
 ; CHECK: bc 4, 2, .LBB[[BB:[0-9_]+]]
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 1, 2
-; CHECK: bc 12, 2, .LBB[[BB]]
+; CHECK: bclr 4, 2, 0
 ; CHECK: .LBB[[BB]]
 ; CHECK: vmr 2, 3
 ; CHECK: blr
@@ -1206,7 +1202,7 @@ entry:
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 3, 4
 ; CHECK: bc 12, 2, .LBB[[BB:[0-9_]+]]
 ; CHECK-DAG: fcmpu {{[0-9]+}}, 1, 2
-; CHECK: bc 4, 2, .LBB[[BB]]
+; CHECK: bclr 12, 2, 0
 ; CHECK: .LBB[[BB]]
 ; CHECK: vmr 2, 3
 ; CHECK: blr