[llvm] r219187 - [FastISel][AArch64] Teach the address computation code to also fold sign-/zero-extends.

Juergen Ributzka juergen at apple.com
Mon Oct 6 20:40:06 PDT 2014


Author: ributzka
Date: Mon Oct  6 22:40:06 2014
New Revision: 219187

URL: http://llvm.org/viewvc/llvm-project?rev=219187&view=rev
Log:
[FastISel][AArch64] Teach the address computation code to also fold sign-/zero-extends.

The code already folds sign-/zero-extends, but only if they are arguments to
mul and shift instructions. This extends the code to also fold them when they
are direct inputs.

Modified:
    llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp
    llvm/trunk/test/CodeGen/AArch64/fast-isel-int-ext.ll

Modified: llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp?rev=219187&r1=219186&r2=219187&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64FastISel.cpp Mon Oct  6 22:40:06 2014
@@ -776,6 +776,35 @@ bool AArch64FastISel::computeAddress(con
       }
     break;
   }
+  case Instruction::SExt:
+  case Instruction::ZExt: {
+    if (!Addr.getReg() || Addr.getOffsetReg())
+      break;
+
+    const Value *Src = nullptr;
+    // Fold the zext or sext when it won't become a noop.
+    if (const auto *ZE = dyn_cast<ZExtInst>(U)) {
+      if (!isIntExtFree(ZE) && ZE->getOperand(0)->getType()->isIntegerTy(32)) {
+        Addr.setExtendType(AArch64_AM::UXTW);
+        Src = ZE->getOperand(0);
+      }
+    } else if (const auto *SE = dyn_cast<SExtInst>(U)) {
+      if (!isIntExtFree(SE) && SE->getOperand(0)->getType()->isIntegerTy(32)) {
+        Addr.setExtendType(AArch64_AM::SXTW);
+        Src = SE->getOperand(0);
+      }
+    }
+
+    if (!Src)
+      break;
+
+    Addr.setShift(0);
+    unsigned Reg = getRegForValue(Src);
+    if (!Reg)
+      return false;
+    Addr.setOffsetReg(Reg);
+    return true;
+  }
   } // end switch
 
   if (Addr.getReg()) {

Modified: llvm/trunk/test/CodeGen/AArch64/fast-isel-int-ext.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/fast-isel-int-ext.ll?rev=219187&r1=219186&r2=219187&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/fast-isel-int-ext.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/fast-isel-int-ext.ll Mon Oct  6 22:40:06 2014
@@ -371,8 +371,7 @@ define i64 @load_register_sext_i32_to_i6
 ; Extend
 define i32 @load_extend_zext_i8_to_i32(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_zext_i8_to_i32
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrb w0, [x0, [[REG]]]
+; CHECK:       ldrb w0, [x0, w1, sxtw]
 ; CHECK-NOT:   uxtb
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -384,8 +383,7 @@ define i32 @load_extend_zext_i8_to_i32(i
 
 define i32 @load_extend_zext_i16_to_i32(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_zext_i16_to_i32
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrh w0, [x0, [[REG]]]
+; CHECK:       ldrh w0, [x0, w1, sxtw]
 ; CHECK-NOT:   uxth
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -397,8 +395,7 @@ define i32 @load_extend_zext_i16_to_i32(
 
 define i64 @load_extend_zext_i8_to_i64(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_zext_i8_to_i64
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrb w0, [x0, [[REG]]]
+; CHECK:       ldrb w0, [x0, w1, sxtw]
 ; CHECK-NOT:   uxtb
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -410,8 +407,7 @@ define i64 @load_extend_zext_i8_to_i64(i
 
 define i64 @load_extend_zext_i16_to_i64(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_zext_i16_to_i64
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrh w0, [x0, [[REG]]]
+; CHECK:       ldrh w0, [x0, w1, sxtw]
 ; CHECK-NOT:   uxth
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -423,8 +419,7 @@ define i64 @load_extend_zext_i16_to_i64(
 
 define i64 @load_extend_zext_i32_to_i64(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_zext_i32_to_i64
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldr w0, [x0, [[REG]]]
+; CHECK:       ldr w0, [x0, w1, sxtw]
 ; CHECK-NOT:   uxtw
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -436,8 +431,7 @@ define i64 @load_extend_zext_i32_to_i64(
 
 define i32 @load_extend_sext_i8_to_i32(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_sext_i8_to_i32
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrsb w0, [x0, [[REG]]]
+; CHECK:       ldrsb w0, [x0, w1, sxtw]
 ; CHECK-NOT:   sxtb
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -449,8 +443,7 @@ define i32 @load_extend_sext_i8_to_i32(i
 
 define i32 @load_extend_sext_i16_to_i32(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_sext_i16_to_i32
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrsh w0, [x0, [[REG]]]
+; CHECK:       ldrsh w0, [x0, w1, sxtw]
 ; CHECK-NOT:   sxth
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -462,8 +455,7 @@ define i32 @load_extend_sext_i16_to_i32(
 
 define i64 @load_extend_sext_i8_to_i64(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_sext_i8_to_i64
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrsb x0, [x0, [[REG]]]
+; CHECK:       ldrsb x0, [x0, w1, sxtw]
 ; CHECK-NOT:   sxtb
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -475,8 +467,7 @@ define i64 @load_extend_sext_i8_to_i64(i
 
 define i64 @load_extend_sext_i16_to_i64(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_sext_i16_to_i64
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrsh x0, [x0, [[REG]]]
+; CHECK:       ldrsh x0, [x0, w1, sxtw]
 ; CHECK-NOT:   sxth
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1
@@ -488,8 +479,7 @@ define i64 @load_extend_sext_i16_to_i64(
 
 define i64 @load_extend_sext_i32_to_i64(i64 %a, i32 %b) {
 ; CHECK-LABEL: load_extend_sext_i32_to_i64
-; CHECK:       sxtw [[REG:x[0-9]+]], w1
-; CHECK-NEXT:  ldrsw x0, [x0, [[REG]]]
+; CHECK:       ldrsw x0, [x0, w1, sxtw]
 ; CHECK-NOT:   sxtw
   %1 = sext i32 %b to i64
   %2 = add i64 %a, %1





More information about the llvm-commits mailing list