[WebAssembly] Teach address folding to fold bitwise-or nodes.

LLVM converts adds into ors when it can prove that the operands don't share
any non-zero bits. Teach address folding to recognize or instructions with
constant operands with this property that can be folded into addresses as
if they were adds.

llvm-svn: 261562

1 files changed, 68 insertions, 0 deletions

diff --git a/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td b/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td
index 096d1875492..a72da44f76c 100644
--- a/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td
+++ b/llvm/lib/Target/WebAssembly/WebAssemblyInstrMemory.td
@@ -28,6 +28,18 @@ def regPlusImm : PatFrag<(ops node:$addr, node:$off),
                          (add node:$addr, node:$off),
                          [{ return N->getFlags()->hasNoUnsignedWrap(); }]>;
 
+// Treat an 'or' node as an 'add' if the or'ed bits are known to be zero.
+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());
+
+  APInt KnownZero0, KnownOne0;
+  CurDAG->computeKnownBits(N->getOperand(0), KnownZero0, KnownOne0, 0);
+  APInt KnownZero1, KnownOne1;
+  CurDAG->computeKnownBits(N->getOperand(1), KnownZero1, KnownOne1, 0);
+  return (~KnownZero0 & ~KnownZero1) == 0;
+}]>;
+
 // GlobalAddresses are conceptually unsigned values, so we can also fold them
 // into immediate values as long as their offsets are non-negative.
 def regPlusGA : PatFrag<(ops node:$addr, node:$off),
@@ -76,6 +88,14 @@ def : Pat<(f32 (load (regPlusImm I32:$addr, imm:$off))),
           (LOAD_F32 imm:$off, $addr, 0)>;
 def : Pat<(f64 (load (regPlusImm I32:$addr, imm:$off))),
           (LOAD_F64 imm:$off, $addr, 0)>;
+def : Pat<(i32 (load (or_is_add I32:$addr, imm:$off))),
+          (LOAD_I32 imm:$off, $addr, 0)>;
+def : Pat<(i64 (load (or_is_add I32:$addr, imm:$off))),
+          (LOAD_I64 imm:$off, $addr, 0)>;
+def : Pat<(f32 (load (or_is_add I32:$addr, imm:$off))),
+          (LOAD_F32 imm:$off, $addr, 0)>;
+def : Pat<(f64 (load (or_is_add I32:$addr, imm:$off))),
+          (LOAD_F64 imm:$off, $addr, 0)>;
 def : Pat<(i32 (load (regPlusGA I32:$addr,
                                 (WebAssemblywrapper tglobaladdr:$off)))),
           (LOAD_I32 tglobaladdr:$off, $addr, 0)>;
@@ -188,6 +208,26 @@ def : Pat<(i64 (sextloadi32 (regPlusImm I32:$addr, imm:$off))),
           (LOAD32_S_I64 imm:$off, $addr, 0)>;
 def : Pat<(i64 (zextloadi32 (regPlusImm I32:$addr, imm:$off))),
           (LOAD32_U_I64 imm:$off, $addr, 0)>;
+def : Pat<(i32 (sextloadi8 (or_is_add I32:$addr, imm:$off))),
+          (LOAD8_S_I32 imm:$off, $addr, 0)>;
+def : Pat<(i32 (zextloadi8 (or_is_add I32:$addr, imm:$off))),
+          (LOAD8_U_I32 imm:$off, $addr, 0)>;
+def : Pat<(i32 (sextloadi16 (or_is_add I32:$addr, imm:$off))),
+          (LOAD16_S_I32 imm:$off, $addr, 0)>;
+def : Pat<(i32 (zextloadi16 (or_is_add I32:$addr, imm:$off))),
+          (LOAD16_U_I32 imm:$off, $addr, 0)>;
+def : Pat<(i64 (sextloadi8 (or_is_add I32:$addr, imm:$off))),
+          (LOAD8_S_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (zextloadi8 (or_is_add I32:$addr, imm:$off))),
+          (LOAD8_U_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (sextloadi16 (or_is_add I32:$addr, imm:$off))),
+          (LOAD16_S_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (zextloadi16 (or_is_add I32:$addr, imm:$off))),
+          (LOAD16_U_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (sextloadi32 (or_is_add I32:$addr, imm:$off))),
+          (LOAD32_S_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (zextloadi32 (or_is_add I32:$addr, imm:$off))),
+          (LOAD32_U_I64 imm:$off, $addr, 0)>;
 def : Pat<(i32 (sextloadi8 (regPlusGA I32:$addr,
                                       (WebAssemblywrapper tglobaladdr:$off)))),
           (LOAD8_S_I32 tglobaladdr:$off, $addr, 0)>;
@@ -332,6 +372,16 @@ def : Pat<(i64 (extloadi16 (regPlusImm I32:$addr, imm:$off))),
           (LOAD16_U_I64 imm:$off, $addr, 0)>;
 def : Pat<(i64 (extloadi32 (regPlusImm I32:$addr, imm:$off))),
           (LOAD32_U_I64 imm:$off, $addr, 0)>;
+def : Pat<(i32 (extloadi8 (or_is_add I32:$addr, imm:$off))),
+          (LOAD8_U_I32 imm:$off, $addr, 0)>;
+def : Pat<(i32 (extloadi16 (or_is_add I32:$addr, imm:$off))),
+          (LOAD16_U_I32 imm:$off, $addr, 0)>;
+def : Pat<(i64 (extloadi8 (or_is_add I32:$addr, imm:$off))),
+          (LOAD8_U_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (extloadi16 (or_is_add I32:$addr, imm:$off))),
+          (LOAD16_U_I64 imm:$off, $addr, 0)>;
+def : Pat<(i64 (extloadi32 (or_is_add I32:$addr, imm:$off))),
+          (LOAD32_U_I64 imm:$off, $addr, 0)>;
 def : Pat<(i32 (extloadi8 (regPlusGA I32:$addr,
                                      (WebAssemblywrapper tglobaladdr:$off)))),
           (LOAD8_U_I32 tglobaladdr:$off, $addr, 0)>;
@@ -433,6 +483,14 @@ def : Pat<(store F32:$val, (regPlusImm I32:$addr, imm:$off)),
           (STORE_F32 imm:$off, I32:$addr, 0, F32:$val)>;
 def : Pat<(store F64:$val, (regPlusImm I32:$addr, imm:$off)),
           (STORE_F64 imm:$off, I32:$addr, 0, F64:$val)>;
+def : Pat<(store I32:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE_I32 imm:$off, I32:$addr, 0, I32:$val)>;
+def : Pat<(store I64:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE_I64 imm:$off, I32:$addr, 0, I64:$val)>;
+def : Pat<(store F32:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE_F32 imm:$off, I32:$addr, 0, F32:$val)>;
+def : Pat<(store F64:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE_F64 imm:$off, I32:$addr, 0, F64:$val)>;
 def : Pat<(store I32:$val, (regPlusGA I32:$addr,
                                       (WebAssemblywrapper tglobaladdr:$off))),
           (STORE_I32 tglobaladdr:$off, I32:$addr, 0, I32:$val)>;
@@ -528,6 +586,16 @@ def : Pat<(truncstorei16 I64:$val, (regPlusImm I32:$addr, imm:$off)),
           (STORE16_I64 imm:$off, I32:$addr, 0, I64:$val)>;
 def : Pat<(truncstorei32 I64:$val, (regPlusImm I32:$addr, imm:$off)),
           (STORE32_I64 imm:$off, I32:$addr, 0, I64:$val)>;
+def : Pat<(truncstorei8 I32:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE8_I32 imm:$off, I32:$addr, 0, I32:$val)>;
+def : Pat<(truncstorei16 I32:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE16_I32 imm:$off, I32:$addr, 0, I32:$val)>;
+def : Pat<(truncstorei8 I64:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE8_I64 imm:$off, I32:$addr, 0, I64:$val)>;
+def : Pat<(truncstorei16 I64:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE16_I64 imm:$off, I32:$addr, 0, I64:$val)>;
+def : Pat<(truncstorei32 I64:$val, (or_is_add I32:$addr, imm:$off)),
+          (STORE32_I64 imm:$off, I32:$addr, 0, I64:$val)>;
 def : Pat<(truncstorei8 I32:$val,
                         (regPlusGA I32:$addr,
                                    (WebAssemblywrapper tglobaladdr:$off))),