[llvm] r300435 - [InstCombine] Add support for turning vector sdiv into udiv.

[Craig Topper via llvm-commits]

Author: ctopper
Date: Sun Apr 16 20:51:19 2017
New Revision: 300435

URL: http://llvm.org/viewvc/llvm-project?rev=300435&view=rev
Log:
[InstCombine] Add support for turning vector sdiv into udiv.

Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
    llvm/trunk/test/Transforms/InstCombine/div-shift.ll
    llvm/trunk/test/Transforms/InstCombine/div.ll

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp?rev=300435&r1=300434&r2=300435&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineMulDivRem.cpp Sun Apr 16 20:51:19 2017
@@ -1238,25 +1238,23 @@ Instruction *InstCombiner::visitSDiv(Bin
 
   // If the sign bits of both operands are zero (i.e. we can prove they are
   // unsigned inputs), turn this into a udiv.
-  if (I.getType()->isIntegerTy()) {
-    APInt Mask(APInt::getSignBit(I.getType()->getPrimitiveSizeInBits()));
-    if (MaskedValueIsZero(Op0, Mask, 0, &I)) {
-      if (MaskedValueIsZero(Op1, Mask, 0, &I)) {
-        // X sdiv Y -> X udiv Y, iff X and Y don't have sign bit set
-        auto *BO = BinaryOperator::CreateUDiv(Op0, Op1, I.getName());
-        BO->setIsExact(I.isExact());
-        return BO;
-      }
+  APInt Mask(APInt::getSignBit(I.getType()->getScalarSizeInBits()));
+  if (MaskedValueIsZero(Op0, Mask, 0, &I)) {
+    if (MaskedValueIsZero(Op1, Mask, 0, &I)) {
+      // X sdiv Y -> X udiv Y, iff X and Y don't have sign bit set
+      auto *BO = BinaryOperator::CreateUDiv(Op0, Op1, I.getName());
+      BO->setIsExact(I.isExact());
+      return BO;
+    }
 
-      if (isKnownToBeAPowerOfTwo(Op1, DL, /*OrZero*/ true, 0, &AC, &I, &DT)) {
-        // X sdiv (1 << Y) -> X udiv (1 << Y) ( -> X u>> Y)
-        // Safe because the only negative value (1 << Y) can take on is
-        // INT_MIN, and X sdiv INT_MIN == X udiv INT_MIN == 0 if X doesn't have
-        // the sign bit set.
-        auto *BO = BinaryOperator::CreateUDiv(Op0, Op1, I.getName());
-        BO->setIsExact(I.isExact());
-        return BO;
-      }
+    if (isKnownToBeAPowerOfTwo(Op1, DL, /*OrZero*/ true, 0, &AC, &I, &DT)) {
+      // X sdiv (1 << Y) -> X udiv (1 << Y) ( -> X u>> Y)
+      // Safe because the only negative value (1 << Y) can take on is
+      // INT_MIN, and X sdiv INT_MIN == X udiv INT_MIN == 0 if X doesn't have
+      // the sign bit set.
+      auto *BO = BinaryOperator::CreateUDiv(Op0, Op1, I.getName());
+      BO->setIsExact(I.isExact());
+      return BO;
     }
   }
 

Modified: llvm/trunk/test/Transforms/InstCombine/div-shift.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/div-shift.ll?rev=300435&r1=300434&r2=300435&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/div-shift.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/div-shift.ll Sun Apr 16 20:51:19 2017
@@ -20,8 +20,8 @@ define <2 x i32> @t1vec(<2 x i16> %x, <2
 ; CHECK-LABEL: @t1vec(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[CONV:%.*]] = zext <2 x i16> [[X:%.*]] to <2 x i32>
-; CHECK-NEXT:    [[S:%.*]] = shl nuw <2 x i32> <i32 2, i32 2>, [[Y:%.*]]
-; CHECK-NEXT:    [[D:%.*]] = sdiv <2 x i32> [[CONV]], [[S]]
+; CHECK-NEXT:    [[TMP0:%.*]] = add <2 x i32> [[Y:%.*]], <i32 1, i32 1>
+; CHECK-NEXT:    [[D:%.*]] = lshr <2 x i32> [[CONV]], [[TMP0]]
 ; CHECK-NEXT:    ret <2 x i32> [[D]]
 ;
 entry:

Modified: llvm/trunk/test/Transforms/InstCombine/div.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/div.ll?rev=300435&r1=300434&r2=300435&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/div.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/div.ll Sun Apr 16 20:51:19 2017
@@ -391,7 +391,7 @@ define i32 @test35(i32 %A) {
 define <2 x i32> @test35vec(<2 x i32> %A) {
 ; CHECK-LABEL: @test35vec(
 ; CHECK-NEXT:    [[AND:%.*]] = and <2 x i32> [[A:%.*]], <i32 2147483647, i32 2147483647>
-; CHECK-NEXT:    [[MUL:%.*]] = sdiv exact <2 x i32> [[AND]], <i32 2147483647, i32 2147483647>
+; CHECK-NEXT:    [[MUL:%.*]] = udiv exact <2 x i32> [[AND]], <i32 2147483647, i32 2147483647>
 ; CHECK-NEXT:    ret <2 x i32> [[MUL]]
 ;
   %and = and <2 x i32> %A, <i32 2147483647, i32 2147483647>
@@ -411,13 +411,10 @@ define i32 @test36(i32 %A) {
   ret i32 %mul
 }
 
-; FIXME: Vector should get same transform as scalar.
-
 define <2 x i32> @test36vec(<2 x i32> %A) {
 ; CHECK-LABEL: @test36vec(
-; CHECK-NEXT:    [[AND:%.*]] = and <2 x i32> %A, <i32 2147483647, i32 2147483647>
-; CHECK-NEXT:    [[SHL:%.*]] = shl nuw nsw <2 x i32> <i32 1, i32 1>, %A
-; CHECK-NEXT:    [[MUL:%.*]] = sdiv exact <2 x i32> [[AND]], [[SHL]]
+; CHECK-NEXT:    [[AND:%.*]] = and <2 x i32> [[A:%.*]], <i32 2147483647, i32 2147483647>
+; CHECK-NEXT:    [[MUL:%.*]] = lshr exact <2 x i32> [[AND]], [[A]]
 ; CHECK-NEXT:    ret <2 x i32> [[MUL]]
 ;
   %and = and <2 x i32> %A, <i32 2147483647, i32 2147483647>