[InstCombine] add tests for missing trunc folds; NFC

As noted in PR35299:
https://bugs.llvm.org/show_bug.cgi?id=35299
...this is likely the root cause for a mis-vectorization transform.

llvm-svn: 318319

1 files changed, 285 insertions, 0 deletions

diff --git a/llvm/test/Transforms/InstCombine/trunc-binop-ext.ll b/llvm/test/Transforms/InstCombine/trunc-binop-ext.ll
new file mode 100644
index 00000000000..bbd2357f1a7
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/trunc-binop-ext.ll
@@ -0,0 +1,285 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+define i16 @narrow_sext_and(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_sext_and(
+; CHECK-NEXT:    [[X321:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = and i32 [[X321]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = sext i16 %x16 to i32
+  %b = and i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_zext_and(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_zext_and(
+; CHECK-NEXT:    [[X32:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = and i32 [[X32]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = zext i16 %x16 to i32
+  %b = and i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_sext_or(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_sext_or(
+; CHECK-NEXT:    [[X321:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = or i32 [[X321]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = sext i16 %x16 to i32
+  %b = or i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_zext_or(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_zext_or(
+; CHECK-NEXT:    [[X32:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = or i32 [[X32]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = zext i16 %x16 to i32
+  %b = or i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_sext_xor(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_sext_xor(
+; CHECK-NEXT:    [[X321:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = xor i32 [[X321]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = sext i16 %x16 to i32
+  %b = xor i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_zext_xor(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_zext_xor(
+; CHECK-NEXT:    [[X32:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = xor i32 [[X32]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = zext i16 %x16 to i32
+  %b = xor i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_sext_add(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_sext_add(
+; CHECK-NEXT:    [[X321:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = add i32 [[X321]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = sext i16 %x16 to i32
+  %b = add i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_zext_add(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_zext_add(
+; CHECK-NEXT:    [[X32:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = add i32 [[X32]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = zext i16 %x16 to i32
+  %b = add i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_sext_mul(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_sext_mul(
+; CHECK-NEXT:    [[X32:%.*]] = sext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = mul i32 [[X32]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = sext i16 %x16 to i32
+  %b = mul i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+define i16 @narrow_zext_mul(i16 %x16, i32 %y32) {
+; CHECK-LABEL: @narrow_zext_mul(
+; CHECK-NEXT:    [[X32:%.*]] = zext i16 %x16 to i32
+; CHECK-NEXT:    [[B:%.*]] = mul i32 [[X32]], %y32
+; CHECK-NEXT:    [[R:%.*]] = trunc i32 [[B]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
+;
+  %x32 = zext i16 %x16 to i32
+  %b = mul i32 %x32, %y32
+  %r = trunc i32 %b to i16
+  ret i16 %r
+}
+
+; Verify that the commuted patterns work. The div is to ensure that complexity-based 
+; canonicalization doesn't swap the binop operands. Use vector types to show those work too.
+
+define <2 x i16> @narrow_sext_and_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_sext_and_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X321:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = and <2 x i32> [[Y32OP0]], [[X321]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = sext <2 x i16> %x16 to <2 x i32>
+  %b = and <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_zext_and_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_zext_and_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X32:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = and <2 x i32> [[Y32OP0]], [[X32]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = zext <2 x i16> %x16 to <2 x i32>
+  %b = and <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_sext_or_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_sext_or_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X321:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = or <2 x i32> [[Y32OP0]], [[X321]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = sext <2 x i16> %x16 to <2 x i32>
+  %b = or <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_zext_or_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_zext_or_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X32:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = or <2 x i32> [[Y32OP0]], [[X32]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = zext <2 x i16> %x16 to <2 x i32>
+  %b = or <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_sext_xor_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_sext_xor_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X321:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = xor <2 x i32> [[Y32OP0]], [[X321]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = sext <2 x i16> %x16 to <2 x i32>
+  %b = xor <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_zext_xor_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_zext_xor_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X32:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = xor <2 x i32> [[Y32OP0]], [[X32]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = zext <2 x i16> %x16 to <2 x i32>
+  %b = xor <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_sext_add_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_sext_add_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X321:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = add <2 x i32> [[Y32OP0]], [[X321]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = sext <2 x i16> %x16 to <2 x i32>
+  %b = add <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_zext_add_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_zext_add_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X32:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = add <2 x i32> [[Y32OP0]], [[X32]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = zext <2 x i16> %x16 to <2 x i32>
+  %b = add <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_sext_mul_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_sext_mul_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X32:%.*]] = sext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = mul <2 x i32> [[Y32OP0]], [[X32]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = sext <2 x i16> %x16 to <2 x i32>
+  %b = mul <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+
+define <2 x i16> @narrow_zext_mul_commute(<2 x i16> %x16, <2 x i32> %y32) {
+; CHECK-LABEL: @narrow_zext_mul_commute(
+; CHECK-NEXT:    [[Y32OP0:%.*]] = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+; CHECK-NEXT:    [[X32:%.*]] = zext <2 x i16> %x16 to <2 x i32>
+; CHECK-NEXT:    [[B:%.*]] = mul <2 x i32> [[Y32OP0]], [[X32]]
+; CHECK-NEXT:    [[R:%.*]] = trunc <2 x i32> [[B]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
+;
+  %y32op0 = sdiv <2 x i32> %y32, <i32 7, i32 -17>
+  %x32 = zext <2 x i16> %x16 to <2 x i32>
+  %b = mul <2 x i32> %y32op0, %x32
+  %r = trunc <2 x i32> %b to <2 x i16>
+  ret <2 x i16> %r
+}
+