Index: llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
===================================================================
--- llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
+++ llvm/trunk/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
@@ -5599,8 +5599,13 @@
   if (!isa<ConstantSDNode>(N1) || !isa<ConstantSDNode>(N2))
     return SDValue();
 
-  // TODO: We should handle other cases of selecting between {-1,0,1} here.
-  if (CondVT == MVT::i1) {
+  // Only do this before legalization to avoid conflicting with target-specific
+  // transforms in the other direction (create a select from a zext/sext). There
+  // is also a target-independent combine here in DAGCombiner in the other
+  // direction for (select Cond, -1, 0) when the condition is not i1.
+  // TODO: This could be generalized for any 2 constants that differ by 1:
+  // add ({s/z}ext Cond), C
+  if (CondVT == MVT::i1 && !LegalOperations) {
     if (isNullConstant(N1) && isOneConstant(N2)) {
       // select Cond, 0, 1 --> zext (!Cond)
       SDValue NotCond = DAG.getNOT(DL, Cond, MVT::i1);
@@ -5608,6 +5613,25 @@
         NotCond = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, NotCond);
       return NotCond;
     }
+    if (isNullConstant(N1) && isAllOnesConstant(N2)) {
+      // select Cond, 0, -1 --> sext (!Cond)
+      SDValue NotCond = DAG.getNOT(DL, Cond, MVT::i1);
+      if (VT != MVT::i1)
+        NotCond = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, NotCond);
+      return NotCond;
+    }
+    if (isOneConstant(N1) && isNullConstant(N2)) {
+      // select Cond, 1, 0 --> zext (Cond)
+      if (VT != MVT::i1)
+        Cond = DAG.getNode(ISD::ZERO_EXTEND, DL, VT, Cond);
+      return Cond;
+    }
+    if (isAllOnesConstant(N1) && isNullConstant(N2)) {
+      // select Cond, -1, 0 --> sext (Cond)
+      if (VT != MVT::i1)
+        Cond = DAG.getNode(ISD::SIGN_EXTEND, DL, VT, Cond);
+      return Cond;
+    }
     return SDValue();
   }
 
@@ -6766,7 +6790,12 @@
 
     if (!VT.isVector()) {
       EVT SetCCVT = getSetCCResultType(N00VT);
-      if (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, N00VT)) {
+      // Don't do this transform for i1 because there's a select transform
+      // that would reverse it.
+      // TODO: We should not do this transform at all without a target hook
+      // because a sext is likely cheaper than a select?
+      if (SetCCVT.getScalarSizeInBits() != 1 &&
+          (!LegalOperations || TLI.isOperationLegal(ISD::SETCC, N00VT))) {
         SDValue SetCC = DAG.getSetCC(DL, SetCCVT, N00, N01, CC);
         return DAG.getSelect(DL, VT, SetCC, ExtTrueVal, Zero);
       }
Index: llvm/trunk/test/CodeGen/AMDGPU/trunc.ll
===================================================================
--- llvm/trunk/test/CodeGen/AMDGPU/trunc.ll
+++ llvm/trunk/test/CodeGen/AMDGPU/trunc.ll
@@ -56,8 +56,7 @@
 }
 
 ; GCN-LABEL: {{^}}trunc_i32_to_i1:
-; GCN: v_and_b32_e32 v{{[0-9]+}}, 1, v{{[0-9]+}}
-; GCN: v_cmp_eq_u32
+; GCN: v_and_b32_e32 [[VREG:v[0-9]+]], 1, v{{[0-9]+}}
 define void @trunc_i32_to_i1(i32 addrspace(1)* %out, i32 addrspace(1)* %ptr) {
   %a = load i32, i32 addrspace(1)* %ptr, align 4
   %trunc = trunc i32 %a to i1
@@ -67,8 +66,7 @@
 }
 
 ; GCN-LABEL: {{^}}trunc_i8_to_i1:
-; GCN: v_and_b32_e32 v{{[0-9]+}}, 1, v{{[0-9]+}}
-; GCN: v_cmp_eq_u32
+; GCN: v_and_b32_e32 [[VREG:v[0-9]+]], 1, v{{[0-9]+}}
 define void @trunc_i8_to_i1(i8 addrspace(1)* %out, i8 addrspace(1)* %ptr) {
   %a = load i8, i8 addrspace(1)* %ptr, align 4
   %trunc = trunc i8 %a to i1
@@ -78,8 +76,7 @@
 }
 
 ; GCN-LABEL: {{^}}sgpr_trunc_i16_to_i1:
-; GCN: s_and_b32 s{{[0-9]+}}, 1, s{{[0-9]+}}
-; GCN: v_cmp_eq_u32
+; GCN: s_and_b32 s{{[0-9]+}}, s{{[0-9]+}}, 1
 define void @sgpr_trunc_i16_to_i1(i16 addrspace(1)* %out, i16 %a) {
   %trunc = trunc i16 %a to i1
   %result = select i1 %trunc, i16 1, i16 0
@@ -88,8 +85,7 @@
 }
 
 ; GCN-LABEL: {{^}}sgpr_trunc_i32_to_i1:
-; GCN: s_and_b32 s{{[0-9]+}}, 1, s{{[0-9]+}}
-; GCN: v_cmp_eq_u32
+; GCN: s_and_b32 s{{[0-9]+}}, s{{[0-9]+}}, 1
 define void @sgpr_trunc_i32_to_i1(i32 addrspace(1)* %out, i32 %a) {
   %trunc = trunc i32 %a to i1
   %result = select i1 %trunc, i32 1, i32 0
Index: llvm/trunk/test/CodeGen/ARM/select_const.ll
===================================================================
--- llvm/trunk/test/CodeGen/ARM/select_const.ll
+++ llvm/trunk/test/CodeGen/ARM/select_const.ll
@@ -40,8 +40,7 @@
 define i32 @select_1_or_0(i1 %cond) {
 ; CHECK-LABEL: select_1_or_0:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    ands r0, r0, #1
-; CHECK-NEXT:    movne r0, #1
+; CHECK-NEXT:    and r0, r0, #1
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 1, i32 0
   ret i32 %sel
@@ -50,8 +49,6 @@
 define i32 @select_1_or_0_zeroext(i1 zeroext %cond) {
 ; CHECK-LABEL: select_1_or_0_zeroext:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    cmp r0, #0
-; CHECK-NEXT:    movne r0, #1
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 1, i32 0
   ret i32 %sel
@@ -60,8 +57,7 @@
 define i32 @select_1_or_0_signext(i1 signext %cond) {
 ; CHECK-LABEL: select_1_or_0_signext:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    ands r0, r0, #1
-; CHECK-NEXT:    movne r0, #1
+; CHECK-NEXT:    and r0, r0, #1
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 1, i32 0
   ret i32 %sel
@@ -72,10 +68,9 @@
 define i32 @select_0_or_neg1(i1 %cond) {
 ; CHECK-LABEL: select_0_or_neg1:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    mvn r1, #0
-; CHECK-NEXT:    tst r0, #1
-; CHECK-NEXT:    movne r1, #0
-; CHECK-NEXT:    mov r0, r1
+; CHECK-NEXT:    mov r1, #1
+; CHECK-NEXT:    bic r0, r1, r0
+; CHECK-NEXT:    rsb r0, r0, #0
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 0, i32 -1
   ret i32 %sel
@@ -84,10 +79,8 @@
 define i32 @select_0_or_neg1_zeroext(i1 zeroext %cond) {
 ; CHECK-LABEL: select_0_or_neg1_zeroext:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    mvn r1, #0
-; CHECK-NEXT:    cmp r0, #0
-; CHECK-NEXT:    movne r1, #0
-; CHECK-NEXT:    mov r0, r1
+; CHECK-NEXT:    eor r0, r0, #1
+; CHECK-NEXT:    rsb r0, r0, #0
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 0, i32 -1
   ret i32 %sel
@@ -96,10 +89,7 @@
 define i32 @select_0_or_neg1_signext(i1 signext %cond) {
 ; CHECK-LABEL: select_0_or_neg1_signext:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    mvn r1, #0
-; CHECK-NEXT:    tst r0, #1
-; CHECK-NEXT:    movne r1, #0
-; CHECK-NEXT:    mov r0, r1
+; CHECK-NEXT:    mvn r0, r0
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 0, i32 -1
   ret i32 %sel
@@ -110,8 +100,8 @@
 define i32 @select_neg1_or_0(i1 %cond) {
 ; CHECK-LABEL: select_neg1_or_0:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    ands r0, r0, #1
-; CHECK-NEXT:    mvnne r0, #0
+; CHECK-NEXT:    and r0, r0, #1
+; CHECK-NEXT:    rsb r0, r0, #0
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 -1, i32 0
   ret i32 %sel
@@ -120,8 +110,7 @@
 define i32 @select_neg1_or_0_zeroext(i1 zeroext %cond) {
 ; CHECK-LABEL: select_neg1_or_0_zeroext:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    cmp r0, #0
-; CHECK-NEXT:    mvnne r0, #0
+; CHECK-NEXT:    rsb r0, r0, #0
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 -1, i32 0
   ret i32 %sel
@@ -130,8 +119,6 @@
 define i32 @select_neg1_or_0_signext(i1 signext %cond) {
 ; CHECK-LABEL: select_neg1_or_0_signext:
 ; CHECK:       @ BB#0:
-; CHECK-NEXT:    ands r0, r0, #1
-; CHECK-NEXT:    mvnne r0, #0
 ; CHECK-NEXT:    mov pc, lr
   %sel = select i1 %cond, i32 -1, i32 0
   ret i32 %sel
Index: llvm/trunk/test/CodeGen/Hexagon/adde.ll
===================================================================
--- llvm/trunk/test/CodeGen/Hexagon/adde.ll
+++ llvm/trunk/test/CodeGen/Hexagon/adde.ll
@@ -1,13 +1,12 @@
 ; RUN: llc -march=hexagon -disable-hsdr -hexagon-expand-condsets=0 -hexagon-bit=0 -disable-post-ra < %s | FileCheck %s
 
-; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,#1)
-; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,#0)
 ; CHECK: r{{[0-9]+:[0-9]+}} = add(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
+; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,#1)
 ; CHECK: p{{[0-9]+}} = cmp.gtu(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
 ; CHECK: p{{[0-9]+}} = cmp.gtu(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
-; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},r{{[0-9]+}},r{{[0-9]+}})
-; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},r{{[0-9]+}},r{{[0-9]+}})
-; CHECK: r{{[0-9]+:[0-9]+}} = combine(r{{[0-9]+}},r{{[0-9]+}})
+; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},#1,#0)
+; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,r{{[0-9]+}})
+; CHECK: r{{[0-9]+:[0-9]+}} = add(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
 ; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},r{{[0-9]+}},r{{[0-9]+}})
 ; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},r{{[0-9]+}},r{{[0-9]+}})
 ; CHECK: r{{[0-9]+:[0-9]+}} = combine(r{{[0-9]+}},r{{[0-9]+}})
Index: llvm/trunk/test/CodeGen/Hexagon/sube.ll
===================================================================
--- llvm/trunk/test/CodeGen/Hexagon/sube.ll
+++ llvm/trunk/test/CodeGen/Hexagon/sube.ll
@@ -1,13 +1,11 @@
 ; RUN: llc -march=hexagon -disable-hsdr -hexagon-expand-condsets=0 -hexagon-bit=0 -disable-post-ra < %s | FileCheck %s
 
-; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,#0)
-; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,#1)
 ; CHECK: p{{[0-9]+}} = cmp.gtu(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
 ; CHECK: r{{[0-9]+:[0-9]+}} = sub(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
-; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},r{{[0-9]+}},r{{[0-9]+}})
-; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},r{{[0-9]+}},r{{[0-9]+}})
+; CHECK: r{{[0-9]+}} = mux(p{{[0-9]+}},#1,#0
+; CHECK: r{{[0-9]+:[0-9]+}} = sub(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
+; CHECK: r{{[0-9]+:[0-9]+}} = combine(#0,r{{[0-9]+}})
 ; CHECK: r{{[0-9]+:[0-9]+}} = sub(r{{[0-9]+:[0-9]+}},r{{[0-9]+:[0-9]+}})
-; CHECK: r{{[0-9]+:[0-9]+}} = combine(r{{[0-9]+}},r{{[0-9]+}})
 
 define void @check_sube_subc(i64 %AL, i64 %AH, i64 %BL, i64 %BH, i64* %RL, i64* %RH) {
 entry:
Index: llvm/trunk/test/CodeGen/NVPTX/add-128bit.ll
===================================================================
--- llvm/trunk/test/CodeGen/NVPTX/add-128bit.ll
+++ llvm/trunk/test/CodeGen/NVPTX/add-128bit.ll
@@ -8,7 +8,7 @@
 ; CHECK:        add.s64
 ; CHECK:        setp.lt.u64
 ; CHECK:        setp.lt.u64
-; CHECK:        selp.b64
+; CHECK:        selp.u64
 ; CHECK:        selp.b64
 ; CHECK:        add.s64
   %t1 = sext i64 %a to i128
Index: llvm/trunk/test/CodeGen/PowerPC/select_const.ll
===================================================================
--- llvm/trunk/test/CodeGen/PowerPC/select_const.ll
+++ llvm/trunk/test/CodeGen/PowerPC/select_const.ll
@@ -39,70 +39,27 @@
 ; select Cond, 1, 0 --> zext (Cond)
 
 define i32 @select_1_or_0(i1 %cond) {
-; ISEL-LABEL: select_1_or_0:
-; ISEL:       # BB#0:
-; ISEL-NEXT:    andi. 3, 3, 1
-; ISEL-NEXT:    li 4, 1
-; ISEL-NEXT:    li 3, 0
-; ISEL-NEXT:    isel 3, 4, 3, 1
-; ISEL-NEXT:    blr
-;
-; NO_ISEL-LABEL: select_1_or_0:
-; NO_ISEL:       # BB#0:
-; NO_ISEL-NEXT:    andi. 3, 3, 1
-; NO_ISEL-NEXT:    li 4, 1
-; NO_ISEL-NEXT:    li 3, 0
-; NO_ISEL-NEXT:    bc 12, 1, .LBB3_1
-; NO_ISEL-NEXT:    blr
-; NO_ISEL-NEXT:  .LBB3_1:
-; NO_ISEL-NEXT:    addi 3, 4, 0
-; NO_ISEL-NEXT:    blr
+; ALL-LABEL: select_1_or_0:
+; ALL:       # BB#0:
+; ALL-NEXT:    clrldi 3, 3, 63
+; ALL-NEXT:    blr
   %sel = select i1 %cond, i32 1, i32 0
   ret i32 %sel
 }
 
 define i32 @select_1_or_0_zeroext(i1 zeroext %cond) {
-; ISEL-LABEL: select_1_or_0_zeroext:
-; ISEL:       # BB#0:
-; ISEL-NEXT:    andi. 3, 3, 1
-; ISEL-NEXT:    li 4, 1
-; ISEL-NEXT:    li 3, 0
-; ISEL-NEXT:    isel 3, 4, 3, 1
-; ISEL-NEXT:    blr
-;
-; NO_ISEL-LABEL: select_1_or_0_zeroext:
-; NO_ISEL:       # BB#0:
-; NO_ISEL-NEXT:    andi. 3, 3, 1
-; NO_ISEL-NEXT:    li 4, 1
-; NO_ISEL-NEXT:    li 3, 0
-; NO_ISEL-NEXT:    bc 12, 1, .LBB4_1
-; NO_ISEL-NEXT:    blr
-; NO_ISEL-NEXT:  .LBB4_1:
-; NO_ISEL-NEXT:    addi 3, 4, 0
-; NO_ISEL-NEXT:    blr
+; ALL-LABEL: select_1_or_0_zeroext:
+; ALL:       # BB#0:
+; ALL-NEXT:    blr
   %sel = select i1 %cond, i32 1, i32 0
   ret i32 %sel
 }
 
 define i32 @select_1_or_0_signext(i1 signext %cond) {
-; ISEL-LABEL: select_1_or_0_signext:
-; ISEL:       # BB#0:
-; ISEL-NEXT:    andi. 3, 3, 1
-; ISEL-NEXT:    li 4, 1
-; ISEL-NEXT:    li 3, 0
-; ISEL-NEXT:    isel 3, 4, 3, 1
-; ISEL-NEXT:    blr
-;
-; NO_ISEL-LABEL: select_1_or_0_signext:
-; NO_ISEL:       # BB#0:
-; NO_ISEL-NEXT:    andi. 3, 3, 1
-; NO_ISEL-NEXT:    li 4, 1
-; NO_ISEL-NEXT:    li 3, 0
-; NO_ISEL-NEXT:    bc 12, 1, .LBB5_1
-; NO_ISEL-NEXT:    blr
-; NO_ISEL-NEXT:  .LBB5_1:
-; NO_ISEL-NEXT:    addi 3, 4, 0
-; NO_ISEL-NEXT:    blr
+; ALL-LABEL: select_1_or_0_signext:
+; ALL:       # BB#0:
+; ALL-NEXT:    clrldi 3, 3, 63
+; ALL-NEXT:    blr
   %sel = select i1 %cond, i32 1, i32 0
   ret i32 %sel
 }
Index: llvm/trunk/test/CodeGen/X86/select_const.ll
===================================================================
--- llvm/trunk/test/CodeGen/X86/select_const.ll
+++ llvm/trunk/test/CodeGen/X86/select_const.ll
@@ -108,10 +108,9 @@
 define i32 @select_neg1_or_0(i1 %cond) {
 ; CHECK-LABEL: select_neg1_or_0:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    xorl %ecx, %ecx
-; CHECK-NEXT:    testb $1, %dil
-; CHECK-NEXT:    movl $-1, %eax
-; CHECK-NEXT:    cmovel %ecx, %eax
+; CHECK-NEXT:    andl $1, %edi
+; CHECK-NEXT:    negl %edi
+; CHECK-NEXT:    movl %edi, %eax
 ; CHECK-NEXT:    retq
   %sel = select i1 %cond, i32 -1, i32 0
   ret i32 %sel
@@ -120,10 +119,8 @@
 define i32 @select_neg1_or_0_zeroext(i1 zeroext %cond) {
 ; CHECK-LABEL: select_neg1_or_0_zeroext:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    xorl %ecx, %ecx
-; CHECK-NEXT:    testb %dil, %dil
-; CHECK-NEXT:    movl $-1, %eax
-; CHECK-NEXT:    cmovel %ecx, %eax
+; CHECK-NEXT:    movzbl %dil, %eax
+; CHECK-NEXT:    negl %eax
 ; CHECK-NEXT:    retq
   %sel = select i1 %cond, i32 -1, i32 0
   ret i32 %sel
@@ -132,10 +129,7 @@
 define i32 @select_neg1_or_0_signext(i1 signext %cond) {
 ; CHECK-LABEL: select_neg1_or_0_signext:
 ; CHECK:       # BB#0:
-; CHECK-NEXT:    xorl %ecx, %ecx
-; CHECK-NEXT:    testb $1, %dil
-; CHECK-NEXT:    movl $-1, %eax
-; CHECK-NEXT:    cmovel %ecx, %eax
+; CHECK-NEXT:    movsbl %dil, %eax
 ; CHECK-NEXT:    retq
   %sel = select i1 %cond, i32 -1, i32 0
   ret i32 %sel