Extend r93152 to work on OR r, r. If the source set bits are known not to overlap, then select as an ADD instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@93191 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 51 insertions, 10 deletions

diff --git a/lib/Target/X86/X86Instr64bit.td b/lib/Target/X86/X86Instr64bit.td
index b2aead6a6d..7077cf9bb0 100644
--- a/lib/Target/X86/X86Instr64bit.td
+++ b/lib/Target/X86/X86Instr64bit.td
@@ -1093,7 +1093,7 @@ let isCommutable = 1 in
 def OR64rr   : RI<0x09, MRMDestReg, (outs GR64:$dst), 
                   (ins GR64:$src1, GR64:$src2),
                   "or{q}\t{$src2, $dst|$dst, $src2}",
-                  [(set GR64:$dst, (or GR64:$src1, GR64:$src2)),
+                  [(set GR64:$dst, (or_not_add GR64:$src1, GR64:$src2)),
                    (implicit EFLAGS)]>;
 def OR64rr_REV : RI<0x0B, MRMSrcReg, (outs GR64:$dst), 
                     (ins GR64:$src1, GR64:$src2),
@@ -2125,13 +2125,16 @@ def : Pat<(store (shld (loadi64 addr:$dst), (i8 imm:$amt1),
                        GR64:$src2, (i8 imm:$amt2)), addr:$dst),
           (SHLD64mri8 addr:$dst, GR64:$src2, (i8 imm:$amt1))>;
 
-// (or x, c) -> (add x, c) if masked bits are known zero.
+// (or x1, x2) -> (add x1, x2) if two operands are known not to share bits.
 def : Pat<(parallel (or_is_add GR64:$src1, i64immSExt8:$src2),
                     (implicit EFLAGS)),
           (ADD64ri8 GR64:$src1, i64immSExt8:$src2)>;
 def : Pat<(parallel (or_is_add GR64:$src1, i64immSExt32:$src2),
                     (implicit EFLAGS)),
           (ADD64ri32 GR64:$src1, i64immSExt32:$src2)>;
+def : Pat<(parallel (or_is_add GR64:$src1, GR64:$src2),
+                    (implicit EFLAGS)),
+          (ADD64rr GR64:$src1, GR64:$src2)>;
 
 // X86 specific add which produces a flag.
 def : Pat<(addc GR64:$src1, GR64:$src2),
diff --git a/lib/Target/X86/X86InstrInfo.td b/lib/Target/X86/X86InstrInfo.td
index 28c5154a56..9b69018fa8 100644
--- a/lib/Target/X86/X86InstrInfo.td
+++ b/lib/Target/X86/X86InstrInfo.td
@@ -497,12 +497,28 @@ def trunc_su : PatFrag<(ops node:$src), (trunc node:$src), [{
 def or_is_add : PatFrag<(ops node:$lhs, node:$rhs), (or node:$lhs, node:$rhs),[{
   if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N->getOperand(1)))
     return CurDAG->MaskedValueIsZero(N->getOperand(0), CN->getAPIntValue());
-  return false;
+  else {
+    unsigned BitWidth = N->getValueType(0).getScalarType().getSizeInBits();
+    APInt Mask = APInt::getAllOnesValue(BitWidth);
+    APInt KnownZero0, KnownOne0;
+    CurDAG->ComputeMaskedBits(N->getOperand(0), Mask, KnownZero0, KnownOne0, 0);
+    APInt KnownZero1, KnownOne1;
+    CurDAG->ComputeMaskedBits(N->getOperand(1), Mask, KnownZero1, KnownOne1, 0);
+    return (~KnownZero0 & ~KnownZero1) == 0;
+  }
 }]>;
 def or_not_add : PatFrag<(ops node:$lhs, node:$rhs),(or node:$lhs, node:$rhs),[{
-  ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N->getOperand(1));
-  if (!CN) return true;
-  return !CurDAG->MaskedValueIsZero(N->getOperand(0), CN->getAPIntValue());
+  if (ConstantSDNode *CN = dyn_cast<ConstantSDNode>(N->getOperand(1)))
+    return !CurDAG->MaskedValueIsZero(N->getOperand(0), CN->getAPIntValue());
+  else {
+    unsigned BitWidth = N->getValueType(0).getScalarType().getSizeInBits();
+    APInt Mask = APInt::getAllOnesValue(BitWidth);
+    APInt KnownZero0, KnownOne0;
+    CurDAG->ComputeMaskedBits(N->getOperand(0), Mask, KnownZero0, KnownOne0, 0);
+    APInt KnownZero1, KnownOne1;
+    CurDAG->ComputeMaskedBits(N->getOperand(1), Mask, KnownZero1, KnownOne1, 0);
+    return (~KnownZero0 & ~KnownZero1) != 0;
+  }
 }]>;
 
 // 'shld' and 'shrd' instruction patterns. Note that even though these have
@@ -1853,12 +1869,12 @@ def OR8rr    : I<0x08, MRMDestReg, (outs GR8 :$dst),
 def OR16rr   : I<0x09, MRMDestReg, (outs GR16:$dst), 
                  (ins GR16:$src1, GR16:$src2),
                  "or{w}\t{$src2, $dst|$dst, $src2}",
-                 [(set GR16:$dst, (or GR16:$src1, GR16:$src2)),
+                 [(set GR16:$dst, (or_not_add GR16:$src1, GR16:$src2)),
                   (implicit EFLAGS)]>, OpSize;
 def OR32rr   : I<0x09, MRMDestReg, (outs GR32:$dst), 
                  (ins GR32:$src1, GR32:$src2),
                  "or{l}\t{$src2, $dst|$dst, $src2}",
-                 [(set GR32:$dst, (or GR32:$src1, GR32:$src2)),
+                 [(set GR32:$dst, (or_not_add GR32:$src1, GR32:$src2)),
                   (implicit EFLAGS)]>;
 }
 
@@ -4659,7 +4675,7 @@ def : Pat<(i16 (anyext (i8 (X86setcc_c X86_COND_B, EFLAGS)))),
 def : Pat<(i32 (anyext (i8 (X86setcc_c X86_COND_B, EFLAGS)))),
           (SETB_C32r)>;
 
-// (or x, c) -> (add x, c) if masked bits are known zero.
+// (or x1, x2) -> (add x1, x2) if two operands are known not to share bits.
 def : Pat<(parallel (or_is_add GR16:$src1, imm:$src2),
                     (implicit EFLAGS)),
           (ADD16ri GR16:$src1, imm:$src2)>;
@@ -4672,6 +4688,12 @@ def : Pat<(parallel (or_is_add GR16:$src1, i16immSExt8:$src2),
 def : Pat<(parallel (or_is_add GR32:$src1, i32immSExt8:$src2),
                     (implicit EFLAGS)),
           (ADD32ri8 GR32:$src1, i32immSExt8:$src2)>;
+def : Pat<(parallel (or_is_add GR16:$src1, GR16:$src2),
+                    (implicit EFLAGS)),
+          (ADD16rr GR16:$src1, GR16:$src2)>;
+def : Pat<(parallel (or_is_add GR32:$src1, GR32:$src2),
+                    (implicit EFLAGS)),
+          (ADD32rr GR32:$src1, GR32:$src2)>;
 
 //===----------------------------------------------------------------------===//
 // EFLAGS-defining Patterns
diff --git a/test/CodeGen/X86/3addr-or.ll b/test/CodeGen/X86/3addr-or.ll
index 395ba46aab..30a1f36850 100644
--- a/test/CodeGen/X86/3addr-or.ll
+++ b/test/CodeGen/X86/3addr-or.ll
@@ -9,3 +9,19 @@ entry:
   %1 = or i32 %0, 3                               ; <i32> [#uses=1]
   ret i32 %1
 }
+
+define i64 @test2(i8 %A, i8 %B) nounwind {
+; CHECK: test2:
+; CHECK: shrq $4
+; CHECK-NOT: movq
+; CHECK-NOT: orq
+; CHECK: leaq
+; CHECK: ret
+  %C = zext i8 %A to i64                          ; <i64> [#uses=1]
+  %D = shl i64 %C, 4                              ; <i64> [#uses=1]
+  %E = and i64 %D, 48                             ; <i64> [#uses=1]
+  %F = zext i8 %B to i64                          ; <i64> [#uses=1]
+  %G = lshr i64 %F, 4                             ; <i64> [#uses=1]
+  %H = or i64 %G, %E                              ; <i64> [#uses=1]
+  ret i64 %H
+}
diff --git a/test/CodeGen/X86/fast-isel.ll b/test/CodeGen/X86/fast-isel.ll
index 3dcd736a14..84b3fd7caf 100644
--- a/test/CodeGen/X86/fast-isel.ll
+++ b/test/CodeGen/X86/fast-isel.ll
@@ -14,7 +14,7 @@ fast:
   %t1 = mul i32 %t0, %s
   %t2 = sub i32 %t1, %s
   %t3 = and i32 %t2, %s
-  %t4 = or i32 %t3, %s
+  %t4 = xor i32 %t3, 3
   %t5 = xor i32 %t4, %s
   %t6 = add i32 %t5, 2
   %t7 = getelementptr i32* %y, i32 1