[InstCombine] Allow common type conversions to i8/i16/i32

This, in instcombine, allows conversions to i8/i16/i32 (very
common cases) even if the resulting type is not legal according
to the data layout. This can often open up extra combine
opportunities.

Differential Revision: https://reviews.llvm.org/D42424



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@323951 91177308-0d34-0410-b5e6-96231b3b80d8

lib/Transforms/InstCombine/InstructionCombining.cpp

@@ -144,11 +144,15 @@ Value *InstCombiner::EmitGEPOffset(User *GEP) {
 /// We don't want to convert from a legal to an illegal type or from a smaller
 /// to a larger illegal type. A width of '1' is always treated as a legal type
 /// because i1 is a fundamental type in IR, and there are many specialized
-/// optimizations for i1 types.
+/// optimizations for i1 types. Widths of 8, 16 or 32 are equally treated as
+/// legal to convert to, in order to open up more combining opportunities.
+/// NOTE: this treats i8, i16 and i32 specially, due to them being so common
+/// from frontend languages.
 bool InstCombiner::shouldChangeType(unsigned FromWidth,
                                     unsigned ToWidth) const {
   bool FromLegal = FromWidth == 1 || DL.isLegalInteger(FromWidth);
-  bool ToLegal = ToWidth == 1 || DL.isLegalInteger(ToWidth);
+  bool ToLegal = ToWidth == 1 || ToWidth == 8 || ToWidth == 16 ||
+      ToWidth == 32 || DL.isLegalInteger(ToWidth);
 
   // If this is a legal integer from type, and the result would be an illegal
   // type, don't do the transformation.

test/Transforms/InstCombine/2010-11-01-lshr-mask.ll

@@ -1,13 +1,12 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt -instcombine -S < %s | FileCheck %s
 
 ; <rdar://problem/8606771>
 define i32 @main(i32 %argc) {
 ; CHECK-LABEL: @main(
-; CHECK-NEXT:    [[TMP3151:%.*]] = trunc i32 %argc to i8
-; CHECK-NEXT:    [[TMP1:%.*]] = shl i8 [[TMP3151]], 5
-; CHECK-NEXT:    [[TMP4126:%.*]] = and i8 [[TMP1]], 64
-; CHECK-NEXT:    [[TMP4127:%.*]] = xor i8 [[TMP4126]], 64
-; CHECK-NEXT:    [[TMP4086:%.*]] = zext i8 [[TMP4127]] to i32
+; CHECK-NEXT:    [[TMP3163:%.*]] = shl i32 %argc, 5
+; CHECK-NEXT:    [[TMP1:%.*]] = and i32 [[TMP3163]], 64
+; CHECK-NEXT:    [[TMP4086:%.*]] = xor i32 [[TMP1]], 64
 ; CHECK-NEXT:    ret i32 [[TMP4086]]
 ;
   %tmp3151 = trunc i32 %argc to i8

test/Transforms/InstCombine/and-narrow.ll

@@ -1,21 +1,15 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
-; RUN: opt < %s -instcombine -data-layout="n8:16:32" -S | FileCheck %s --check-prefix=ALL --check-prefix=LEGAL8
-; RUN: opt < %s -instcombine -data-layout="n16"      -S | FileCheck %s --check-prefix=ALL --check-prefix=LEGAL16
+; RUN: opt < %s -instcombine -data-layout="n8:16:32" -S | FileCheck %s
+; RUN: opt < %s -instcombine -data-layout="n16"      -S | FileCheck %s
 
 ; PR35792 - https://bugs.llvm.org/show_bug.cgi?id=35792
 
 define i16 @zext_add(i8 %x) {
-; LEGAL8-LABEL: @zext_add(
-; LEGAL8-NEXT:    [[TMP1:%.*]] = add i8 [[X:%.*]], 44
-; LEGAL8-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
-; LEGAL8-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
-; LEGAL8-NEXT:    ret i16 [[R]]
-;
-; LEGAL16-LABEL: @zext_add(
-; LEGAL16-NEXT:    [[Z:%.*]] = zext i8 [[X:%.*]] to i16
-; LEGAL16-NEXT:    [[B:%.*]] = add nuw nsw i16 [[Z]], 44
-; LEGAL16-NEXT:    [[R:%.*]] = and i16 [[B]], [[Z]]
-; LEGAL16-NEXT:    ret i16 [[R]]
+; CHECK-LABEL: @zext_add(
+; CHECK-NEXT:    [[TMP1:%.*]] = add i8 [[X:%.*]], 44
+; CHECK-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
 ;
   %z = zext i8 %x to i16
   %b = add i16 %z, 44
@@ -24,17 +18,11 @@ define i16 @zext_add(i8 %x) {
 }
 
 define i16 @zext_sub(i8 %x) {
-; LEGAL8-LABEL: @zext_sub(
-; LEGAL8-NEXT:    [[TMP1:%.*]] = sub i8 -5, [[X:%.*]]
-; LEGAL8-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
-; LEGAL8-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
-; LEGAL8-NEXT:    ret i16 [[R]]
-;
-; LEGAL16-LABEL: @zext_sub(
-; LEGAL16-NEXT:    [[Z:%.*]] = zext i8 [[X:%.*]] to i16
-; LEGAL16-NEXT:    [[B:%.*]] = sub nsw i16 251, [[Z]]
-; LEGAL16-NEXT:    [[R:%.*]] = and i16 [[B]], [[Z]]
-; LEGAL16-NEXT:    ret i16 [[R]]
+; CHECK-LABEL: @zext_sub(
+; CHECK-NEXT:    [[TMP1:%.*]] = sub i8 -5, [[X:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
 ;
   %z = zext i8 %x to i16
   %b = sub i16 -5, %z
@@ -43,17 +31,11 @@ define i16 @zext_sub(i8 %x) {
 }
 
 define i16 @zext_mul(i8 %x) {
-; LEGAL8-LABEL: @zext_mul(
-; LEGAL8-NEXT:    [[TMP1:%.*]] = mul i8 [[X:%.*]], 3
-; LEGAL8-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
-; LEGAL8-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
-; LEGAL8-NEXT:    ret i16 [[R]]
-;
-; LEGAL16-LABEL: @zext_mul(
-; LEGAL16-NEXT:    [[Z:%.*]] = zext i8 [[X:%.*]] to i16
-; LEGAL16-NEXT:    [[B:%.*]] = mul nuw nsw i16 [[Z]], 3
-; LEGAL16-NEXT:    [[R:%.*]] = and i16 [[B]], [[Z]]
-; LEGAL16-NEXT:    ret i16 [[R]]
+; CHECK-LABEL: @zext_mul(
+; CHECK-NEXT:    [[TMP1:%.*]] = mul i8 [[X:%.*]], 3
+; CHECK-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
 ;
   %z = zext i8 %x to i16
   %b = mul i16 %z, 3
@@ -62,17 +44,11 @@ define i16 @zext_mul(i8 %x) {
 }
 
 define i16 @zext_lshr(i8 %x) {
-; LEGAL8-LABEL: @zext_lshr(
-; LEGAL8-NEXT:    [[TMP1:%.*]] = lshr i8 [[X:%.*]], 4
-; LEGAL8-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
-; LEGAL8-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
-; LEGAL8-NEXT:    ret i16 [[R]]
-;
-; LEGAL16-LABEL: @zext_lshr(
-; LEGAL16-NEXT:    [[Z:%.*]] = zext i8 [[X:%.*]] to i16
-; LEGAL16-NEXT:    [[B:%.*]] = lshr i16 [[Z]], 4
-; LEGAL16-NEXT:    [[R:%.*]] = and i16 [[B]], [[Z]]
-; LEGAL16-NEXT:    ret i16 [[R]]
+; CHECK-LABEL: @zext_lshr(
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i8 [[X:%.*]], 4
+; CHECK-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
 ;
   %z = zext i8 %x to i16
   %b = lshr i16 %z, 4
@@ -81,17 +57,11 @@ define i16 @zext_lshr(i8 %x) {
 }
 
 define i16 @zext_ashr(i8 %x) {
-; LEGAL8-LABEL: @zext_ashr(
-; LEGAL8-NEXT:    [[TMP1:%.*]] = lshr i8 [[X:%.*]], 2
-; LEGAL8-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
-; LEGAL8-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
-; LEGAL8-NEXT:    ret i16 [[R]]
-;
-; LEGAL16-LABEL: @zext_ashr(
-; LEGAL16-NEXT:    [[Z:%.*]] = zext i8 [[X:%.*]] to i16
-; LEGAL16-NEXT:    [[TMP1:%.*]] = lshr i16 [[Z]], 2
-; LEGAL16-NEXT:    [[R:%.*]] = and i16 [[TMP1]], [[Z]]
-; LEGAL16-NEXT:    ret i16 [[R]]
+; CHECK-LABEL: @zext_ashr(
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr i8 [[X:%.*]], 2
+; CHECK-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
 ;
   %z = zext i8 %x to i16
   %b = ashr i16 %z, 2
@@ -100,17 +70,11 @@ define i16 @zext_ashr(i8 %x) {
 }
 
 define i16 @zext_shl(i8 %x) {
-; LEGAL8-LABEL: @zext_shl(
-; LEGAL8-NEXT:    [[TMP1:%.*]] = shl i8 [[X:%.*]], 3
-; LEGAL8-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
-; LEGAL8-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
-; LEGAL8-NEXT:    ret i16 [[R]]
-;
-; LEGAL16-LABEL: @zext_shl(
-; LEGAL16-NEXT:    [[Z:%.*]] = zext i8 [[X:%.*]] to i16
-; LEGAL16-NEXT:    [[B:%.*]] = shl nuw nsw i16 [[Z]], 3
-; LEGAL16-NEXT:    [[R:%.*]] = and i16 [[B]], [[Z]]
-; LEGAL16-NEXT:    ret i16 [[R]]
+; CHECK-LABEL: @zext_shl(
+; CHECK-NEXT:    [[TMP1:%.*]] = shl i8 [[X:%.*]], 3
+; CHECK-NEXT:    [[TMP2:%.*]] = and i8 [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext i8 [[TMP2]] to i16
+; CHECK-NEXT:    ret i16 [[R]]
 ;
   %z = zext i8 %x to i16
   %b = shl i16 %z, 3
@@ -119,11 +83,11 @@ define i16 @zext_shl(i8 %x) {
 }
 
 define <2 x i16> @zext_add_vec(<2 x i8> %x) {
-; ALL-LABEL: @zext_add_vec(
-; ALL-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 44, i8 42>
-; ALL-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
-; ALL-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_add_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = add <2 x i8> [[X:%.*]], <i8 44, i8 42>
+; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = add <2 x i16> %z, <i16 44, i16 42>
@@ -132,11 +96,11 @@ define <2 x i16> @zext_add_vec(<2 x i8> %x) {
 }
 
 define <2 x i16> @zext_sub_vec(<2 x i8> %x) {
-; ALL-LABEL: @zext_sub_vec(
-; ALL-NEXT:    [[TMP1:%.*]] = sub <2 x i8> <i8 -5, i8 -4>, [[X:%.*]]
-; ALL-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
-; ALL-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_sub_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = sub <2 x i8> <i8 -5, i8 -4>, [[X:%.*]]
+; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = sub <2 x i16> <i16 -5, i16 -4>, %z
@@ -145,11 +109,11 @@ define <2 x i16> @zext_sub_vec(<2 x i8> %x) {
 }
 
 define <2 x i16> @zext_mul_vec(<2 x i8> %x) {
-; ALL-LABEL: @zext_mul_vec(
-; ALL-NEXT:    [[TMP1:%.*]] = mul <2 x i8> [[X:%.*]], <i8 3, i8 -2>
-; ALL-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
-; ALL-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_mul_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = mul <2 x i8> [[X:%.*]], <i8 3, i8 -2>
+; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = mul <2 x i16> %z, <i16 3, i16 -2>
@@ -158,11 +122,11 @@ define <2 x i16> @zext_mul_vec(<2 x i8> %x) {
 }
 
 define <2 x i16> @zext_lshr_vec(<2 x i8> %x) {
-; ALL-LABEL: @zext_lshr_vec(
-; ALL-NEXT:    [[TMP1:%.*]] = lshr <2 x i8> [[X:%.*]], <i8 4, i8 2>
-; ALL-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
-; ALL-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_lshr_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i8> [[X:%.*]], <i8 4, i8 2>
+; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = lshr <2 x i16> %z, <i16 4, i16 2>
@@ -171,11 +135,11 @@ define <2 x i16> @zext_lshr_vec(<2 x i8> %x) {
 }
 
 define <2 x i16> @zext_ashr_vec(<2 x i8> %x) {
-; ALL-LABEL: @zext_ashr_vec(
-; ALL-NEXT:    [[TMP1:%.*]] = lshr <2 x i8> [[X:%.*]], <i8 2, i8 3>
-; ALL-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
-; ALL-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_ashr_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = lshr <2 x i8> [[X:%.*]], <i8 2, i8 3>
+; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = ashr <2 x i16> %z, <i16 2, i16 3>
@@ -184,11 +148,11 @@ define <2 x i16> @zext_ashr_vec(<2 x i8> %x) {
 }
 
 define <2 x i16> @zext_shl_vec(<2 x i8> %x) {
-; ALL-LABEL: @zext_shl_vec(
-; ALL-NEXT:    [[TMP1:%.*]] = shl <2 x i8> [[X:%.*]], <i8 3, i8 2>
-; ALL-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
-; ALL-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_shl_vec(
+; CHECK-NEXT:    [[TMP1:%.*]] = shl <2 x i8> [[X:%.*]], <i8 3, i8 2>
+; CHECK-NEXT:    [[TMP2:%.*]] = and <2 x i8> [[TMP1]], [[X]]
+; CHECK-NEXT:    [[R:%.*]] = zext <2 x i8> [[TMP2]] to <2 x i16>
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = shl <2 x i16> %z, <i16 3, i16 2>
@@ -199,11 +163,11 @@ define <2 x i16> @zext_shl_vec(<2 x i8> %x) {
 ; Don't create poison by narrowing a shift below the shift amount.
 
 define <2 x i16> @zext_lshr_vec_overshift(<2 x i8> %x) {
-; ALL-LABEL: @zext_lshr_vec_overshift(
-; ALL-NEXT:    [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i16>
-; ALL-NEXT:    [[B:%.*]] = lshr <2 x i16> [[Z]], <i16 4, i16 8>
-; ALL-NEXT:    [[R:%.*]] = and <2 x i16> [[B]], [[Z]]
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_lshr_vec_overshift(
+; CHECK-NEXT:    [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i16>
+; CHECK-NEXT:    [[B:%.*]] = lshr <2 x i16> [[Z]], <i16 4, i16 8>
+; CHECK-NEXT:    [[R:%.*]] = and <2 x i16> [[B]], [[Z]]
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = lshr <2 x i16> %z, <i16 4, i16 8>
@@ -214,11 +178,11 @@ define <2 x i16> @zext_lshr_vec_overshift(<2 x i8> %x) {
 ; Don't create poison by narrowing a shift below the shift amount.
 
 define <2 x i16> @zext_shl_vec_overshift(<2 x i8> %x) {
-; ALL-LABEL: @zext_shl_vec_overshift(
-; ALL-NEXT:    [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i16>
-; ALL-NEXT:    [[B:%.*]] = shl <2 x i16> [[Z]], <i16 8, i16 2>
-; ALL-NEXT:    [[R:%.*]] = and <2 x i16> [[B]], [[Z]]
-; ALL-NEXT:    ret <2 x i16> [[R]]
+; CHECK-LABEL: @zext_shl_vec_overshift(
+; CHECK-NEXT:    [[Z:%.*]] = zext <2 x i8> [[X:%.*]] to <2 x i16>
+; CHECK-NEXT:    [[B:%.*]] = shl <2 x i16> [[Z]], <i16 8, i16 2>
+; CHECK-NEXT:    [[R:%.*]] = and <2 x i16> [[B]], [[Z]]
+; CHECK-NEXT:    ret <2 x i16> [[R]]
 ;
   %z = zext <2 x i8> %x to <2 x i16>
   %b = shl <2 x i16> %z, <i16 8, i16 2>

test/Transforms/InstCombine/select-bitext.ll

@@ -112,8 +112,9 @@ define <2 x i64> @trunc_sel_larger_sext_vec(<2 x i32> %a, <2 x i1> %cmp) {
 
 define i32 @trunc_sel_smaller_sext(i64 %a, i1 %cmp) {
 ; CHECK-LABEL: @trunc_sel_smaller_sext(
-; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i64 %a to i16
-; CHECK-NEXT:    [[TMP1:%.*]] = sext i16 [[TRUNC]] to i32
+; CHECK-NEXT:    [[TRUNC:%.*]] = trunc i64 %a to i32
+; CHECK-NEXT:    [[SEXT:%.*]] = shl i32 [[TRUNC]], 16
+; CHECK-NEXT:    [[TMP1:%.*]] = ashr exact i32 [[SEXT]], 16
 ; CHECK-NEXT:    [[EXT:%.*]] = select i1 %cmp, i32 [[TMP1]], i32 42
 ; CHECK-NEXT:    ret i32 [[EXT]]
 ;

test/Transforms/InstCombine/should-change-type.ll

@@ -0,0 +1,57 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt < %s -instcombine -S | FileCheck %s
+target datalayout = "n64"
+
+; Tests for removing zext/trunc from/to i8, i16 and i32, even if it is
+; not a legal type.
+
+define i8 @test1(i8 %x, i8 %y) {
+; CHECK-LABEL: @test1(
+; CHECK-NEXT:    [[C:%.*]] = add i8 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i8 [[C]]
+;
+  %xz = zext i8 %x to i64
+  %yz = zext i8 %y to i64
+  %c = add i64 %xz, %yz
+  %d = trunc i64 %c to i8
+  ret i8 %d
+}
+
+define i16 @test2(i16 %x, i16 %y) {
+; CHECK-LABEL: @test2(
+; CHECK-NEXT:    [[C:%.*]] = add i16 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i16 [[C]]
+;
+  %xz = zext i16 %x to i64
+  %yz = zext i16 %y to i64
+  %c = add i64 %xz, %yz
+  %d = trunc i64 %c to i16
+  ret i16 %d
+}
+
+define i32 @test3(i32 %x, i32 %y) {
+; CHECK-LABEL: @test3(
+; CHECK-NEXT:    [[C:%.*]] = add i32 [[X:%.*]], [[Y:%.*]]
+; CHECK-NEXT:    ret i32 [[C]]
+;
+  %xz = zext i32 %x to i64
+  %yz = zext i32 %y to i64
+  %c = add i64 %xz, %yz
+  %d = trunc i64 %c to i32
+  ret i32 %d
+}
+
+define i9 @test4(i9 %x, i9 %y) {
+; CHECK-LABEL: @test4(
+; CHECK-NEXT:    [[XZ:%.*]] = zext i9 [[X:%.*]] to i64
+; CHECK-NEXT:    [[YZ:%.*]] = zext i9 [[Y:%.*]] to i64
+; CHECK-NEXT:    [[C:%.*]] = add nuw nsw i64 [[XZ]], [[YZ]]
+; CHECK-NEXT:    [[D:%.*]] = trunc i64 [[C]] to i9
+; CHECK-NEXT:    ret i9 [[D]]
+;
+  %xz = zext i9 %x to i64
+  %yz = zext i9 %y to i64
+  %c = add i64 %xz, %yz
+  %d = trunc i64 %c to i9
+  ret i9 %d
+}