[llvm] r293434 - [InstCombine] add tests for shl(shr X, C1), C2 transforms; NFC

[Sanjay Patel via llvm-commits]

Author: spatel
Date: Sun Jan 29 10:52:59 2017
New Revision: 293434

URL: http://llvm.org/viewvc/llvm-project?rev=293434&view=rev
Log:
[InstCombine] add tests for shl(shr X, C1), C2 transforms; NFC

Modified:
    llvm/trunk/test/Transforms/InstCombine/shift.ll

Modified: llvm/trunk/test/Transforms/InstCombine/shift.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/shift.ll?rev=293434&r1=293433&r2=293434&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/shift.ll (original)
+++ llvm/trunk/test/Transforms/InstCombine/shift.ll Sun Jan 29 10:52:59 2017
@@ -812,6 +812,8 @@ define i32 @test47(i32 %a) {
   ret i32 %z
 }
 
+; (X >>u,exact C1) << C2 --> X << (C2-C1) when C2 > C1
+
 define i32 @test48(i32 %x) {
 ; CHECK-LABEL: @test48(
 ; CHECK-NEXT:    [[B:%.*]] = shl i32 %x, 2
@@ -822,6 +824,33 @@ define i32 @test48(i32 %x) {
   ret i32 %B
 }
 
+; Verify that wrap flags are preserved from the original 'shl'.
+
+define i32 @test48_nuw_nsw(i32 %x) {
+; CHECK-LABEL: @test48_nuw_nsw(
+; CHECK-NEXT:    [[B:%.*]] = shl nuw nsw i32 %x, 2
+; CHECK-NEXT:    ret i32 [[B]]
+;
+  %A = lshr exact i32 %x, 1
+  %B = shl nuw nsw i32 %A, 3
+  ret i32 %B
+}
+
+; (X >>u,exact C1) << C2 --> X << (C2-C1) when splatted C2 > C1
+
+define <2 x i32> @test48_splat_vec(<2 x i32> %x) {
+; CHECK-LABEL: @test48_splat_vec(
+; CHECK-NEXT:    [[A:%.*]] = lshr exact <2 x i32> %x, <i32 1, i32 1>
+; CHECK-NEXT:    [[B:%.*]] = shl nuw nsw <2 x i32> [[A]], <i32 3, i32 3>
+; CHECK-NEXT:    ret <2 x i32> [[B]]
+;
+  %A = lshr exact <2 x i32> %x, <i32 1, i32 1>
+  %B = shl nsw nuw <2 x i32> %A, <i32 3, i32 3>
+  ret <2 x i32> %B
+}
+
+; (X >>s,exact C1) << C2 --> X << (C2-C1) when C2 > C1
+
 define i32 @test49(i32 %x) {
 ; CHECK-LABEL: @test49(
 ; CHECK-NEXT:    [[B:%.*]] = shl i32 %x, 2
@@ -832,6 +861,31 @@ define i32 @test49(i32 %x) {
   ret i32 %B
 }
 
+; Verify that wrap flags are preserved from the original 'shl'.
+
+define i32 @test49_nuw_nsw(i32 %x) {
+; CHECK-LABEL: @test49_nuw_nsw(
+; CHECK-NEXT:    [[B:%.*]] = shl nuw nsw i32 %x, 2
+; CHECK-NEXT:    ret i32 [[B]]
+;
+  %A = ashr exact i32 %x, 1
+  %B = shl nuw nsw i32 %A, 3
+  ret i32 %B
+}
+
+; (X >>s,exact C1) << C2 --> X << (C2-C1) when splatted C2 > C1
+
+define <2 x i32> @test49_splat_vec(<2 x i32> %x) {
+; CHECK-LABEL: @test49_splat_vec(
+; CHECK-NEXT:    [[A:%.*]] = ashr exact <2 x i32> %x, <i32 1, i32 1>
+; CHECK-NEXT:    [[B:%.*]] = shl nuw nsw <2 x i32> [[A]], <i32 3, i32 3>
+; CHECK-NEXT:    ret <2 x i32> [[B]]
+;
+  %A = ashr exact <2 x i32> %x, <i32 1, i32 1>
+  %B = shl nsw nuw <2 x i32> %A, <i32 3, i32 3>
+  ret <2 x i32> %B
+}
+
 define i32 @test50(i32 %x) {
 ; CHECK-LABEL: @test50(
 ; CHECK-NEXT:    [[B:%.*]] = ashr i32 %x, 2
@@ -1055,10 +1109,10 @@ define <2 x i65> @test_63(<2 x i64> %t)
 
 define i64 @test_64(i32 %t) {
 ; CHECK-LABEL: @test_64(
-; CHECK-NEXT: [[SHL:%.*]] = shl i32 %t, 8
-; CHECK-NEXT: [[EXT:%.*]] = zext i32 [[SHL]] to i64
-; CHECK-NEXT: ret i64 [[EXT]]
-
+; CHECK-NEXT:    [[TMP1:%.*]] = shl i32 %t, 8
+; CHECK-NEXT:    [[SHL:%.*]] = zext i32 [[TMP1]] to i64
+; CHECK-NEXT:    ret i64 [[SHL]]
+;
   %and = and i32 %t, 16777215
   %ext = zext i32 %and to i64
   %shl = shl i64 %ext, 8