Added inst combine transforms for single bit tests from Chris's note

if ((x & C) == 0) x |= C becomes x |= C
if ((x & C) != 0) x ^= C becomes x &= ~C
if ((x & C) == 0) x ^= C becomes x |= C
if ((x & C) != 0) x &= ~C becomes x &= ~C
if ((x & C) == 0) x &= ~C becomes nothing

Differential Revision: http://reviews.llvm.org/D3777

llvm-svn: 210006

1 files changed, 105 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/select.ll b/llvm/test/Transforms/InstCombine/select.ll
index 2213be1f511..23a891a7b2a 100644
--- a/llvm/test/Transforms/InstCombine/select.ll
+++ b/llvm/test/Transforms/InstCombine/select.ll
@@ -996,6 +996,111 @@ define <2 x i32> @select_icmp_eq_and_1_0_or_vector_of_2s(i32 %x, <2 x i32> %y) {
   ret <2 x i32> %select
 }
 
+; CHECK-LABEL: @select_icmp_and_8_eq_0_or_8(
+; CHECK-NEXT: [[OR:%[a-z0-9]+]] = or i32 %x, 8
+; CHECK-NEXT: ret i32 [[OR]]
+define i32 @select_icmp_and_8_eq_0_or_8(i32 %x) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %or = or i32 %x, 8
+  %or.x = select i1 %cmp, i32 %or, i32 %x
+  ret i32 %or.x
+}
+
+; CHECK-LABEL: @select_icmp_and_8_ne_0_xor_8(
+; CHECK-NEXT: [[AND:%[a-z0-9]+]] = and i32 %x, -9
+; CHECK-NEXT: ret i32 [[AND]]
+define i32 @select_icmp_and_8_ne_0_xor_8(i32 %x) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %xor = xor i32 %x, 8
+  %x.xor = select i1 %cmp, i32 %x, i32 %xor
+  ret i32 %x.xor
+}
+
+; CHECK-LABEL: @select_icmp_and_8_eq_0_xor_8(
+; CHECK-NEXT: [[OR:%[a-z0-9]+]] = or i32 %x, 8
+; CHECK-NEXT: ret i32 [[OR]]
+define i32 @select_icmp_and_8_eq_0_xor_8(i32 %x) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %xor = xor i32 %x, 8
+  %xor.x = select i1 %cmp, i32 %xor, i32 %x
+  ret i32 %xor.x
+}
+
+; CHECK-LABEL: @select_icmp_and_8_ne_0_and_not_8(
+; CHECK-NEXT: [[AND:%[a-z0-9]+]] = and i32 %x, -9
+; CHECK-NEXT: ret i32 [[AND]]
+define i32 @select_icmp_and_8_ne_0_and_not_8(i32 %x) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %and1 = and i32 %x, -9
+  %x.and1 = select i1 %cmp, i32 %x, i32 %and1
+  ret i32 %x.and1
+}
+
+; CHECK-LABEL: @select_icmp_and_8_eq_0_and_not_8(
+; CHECK-NEXT: ret i32 %x
+define i32 @select_icmp_and_8_eq_0_and_not_8(i32 %x) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %and1 = and i32 %x, -9
+  %and1.x = select i1 %cmp, i32 %and1, i32 %x
+  ret i32 %and1.x
+}
+
+; CHECK-LABEL: @select_icmp_x_and_8_eq_0_y_xor_8(
+; CHECK: select i1 %cmp, i64 %y, i64 %xor
+define i64 @select_icmp_x_and_8_eq_0_y_xor_8(i32 %x, i64 %y) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %xor = xor i64 %y, 8
+  %y.xor = select i1 %cmp, i64 %y, i64 %xor
+  ret i64 %y.xor
+}
+
+; CHECK-LABEL: @select_icmp_x_and_8_eq_0_y_and_not_8(
+; CHECK: select i1 %cmp, i64 %y, i64 %and1
+define i64 @select_icmp_x_and_8_eq_0_y_and_not_8(i32 %x, i64 %y) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %and1 = and i64 %y, -9
+  %y.and1 = select i1 %cmp, i64 %y, i64 %and1
+  ret i64 %y.and1
+}
+
+; CHECK-LABEL: @select_icmp_x_and_8_ne_0_y_xor_8(
+; CHECK: select i1 %cmp, i64 %xor, i64 %y
+define i64 @select_icmp_x_and_8_ne_0_y_xor_8(i32 %x, i64 %y) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %xor = xor i64 %y, 8
+  %xor.y = select i1 %cmp, i64 %xor, i64 %y
+  ret i64 %xor.y
+}
+
+; CHECK-LABEL: @select_icmp_x_and_8_ne_0_y_and_not_8(
+; CHECK: select i1 %cmp, i64 %and1, i64 %y
+define i64 @select_icmp_x_and_8_ne_0_y_and_not_8(i32 %x, i64 %y) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %and1 = and i64 %y, -9
+  %and1.y = select i1 %cmp, i64 %and1, i64 %y
+  ret i64 %and1.y
+}
+
+; CHECK-LABEL: @select_icmp_x_and_8_ne_0_y_or_8(
+; CHECK: xor i64 %1, 8
+; CHECK: or i64 %2, %y
+define i64 @select_icmp_x_and_8_ne_0_y_or_8(i32 %x, i64 %y) {
+  %and = and i32 %x, 8
+  %cmp = icmp eq i32 %and, 0
+  %or = or i64 %y, 8
+  %or.y = select i1 %cmp, i64 %or, i64 %y
+  ret i64 %or.y
+}
+
 define i32 @test65(i64 %x) {
   %1 = and i64 %x, 16
   %2 = icmp ne i64 %1, 0