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llvm-project/llvm/test/Transforms/InstCombine/iX-ext-split.ll
Muhammad Bassiouni c662a9d303
[InstCombine] recognize missed i128 split optimization (#129363) 
This pr fixes #126056, recognising a split i128 extension optimization.

Proof for working optimization:

```llvm
define i128 @src(i32 noundef %x) {
entry:
  %coerce.sroa.0.0.extract.trunc = sext i32 %x to i64
  %0 = ashr i32 %x, 31
  %coerce.sroa.2.0.extract.trunc = sext i32 %0 to i64
  %x.sroa.2.0.insert.ext.i = zext i64 %coerce.sroa.2.0.extract.trunc to i128
  %x.sroa.2.0.insert.shift.i = shl nuw i128 %x.sroa.2.0.insert.ext.i, 64
  %x.sroa.0.0.insert.ext.i = zext i64 %coerce.sroa.0.0.extract.trunc to i128
  %x.sroa.0.0.insert.insert.i = or disjoint i128 %x.sroa.2.0.insert.shift.i, %x.sroa.0.0.insert.ext.i
  ret i128 %x.sroa.0.0.insert.insert.i
}

define i128 @tgt(i32 noundef %x)  {
  %x.sroa.0.0.insert.insert.i = sext i32 %x to i128
  ret i128 %x.sroa.0.0.insert.insert.i
}
```
2025-03-06 09:42:52 +00:00

197 lines
5.9 KiB
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; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
; RUN: opt < %s -passes=instcombine -S | FileCheck %s
; PR129363
; ext split from i32 to i128
define i128 @i128_ext_split(i32 noundef %x) {
; CHECK-LABEL: define i128 @i128_ext_split(
; CHECK-SAME: i32 noundef [[X:%.*]]) {
; CHECK-NEXT: [[XX:%.*]] = sext i32 [[X]] to i128
; CHECK-NEXT: ret i128 [[XX]]
;
%LowerSrc = sext i32 %x to i64
%sign = ashr i32 %x, 31
%UpperSrc = sext i32 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 64
%lo = zext i64 %LowerSrc to i128
%res = or disjoint i128 %hi, %lo
ret i128 %res
}
; ext split from i32 to i128
define void @i128_ext_split_store(i32 %x, ptr %out) {
; CHECK-LABEL: define void @i128_ext_split_store(
; CHECK-SAME: i32 [[X:%.*]], ptr [[OUT:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = sext i32 [[X]] to i128
; CHECK-NEXT: store i128 [[RES]], ptr [[OUT]], align 16
; CHECK-NEXT: ret void
;
entry:
%LowerSrc = sext i32 %x to i64
%lo = zext i64 %LowerSrc to i128
%sign = ashr i32 %x, 31
%UpperSrc = sext i32 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 64
%res = or disjoint i128 %hi, %lo
store i128 %res, ptr %out, align 16
ret void
}
; ext split from i16 to i64
define void @i64_ext_split_store(i16 %x, ptr %out) {
; CHECK-LABEL: define void @i64_ext_split_store(
; CHECK-SAME: i16 [[X:%.*]], ptr [[OUT:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = sext i16 [[X]] to i64
; CHECK-NEXT: store i64 [[RES]], ptr [[OUT]], align 16
; CHECK-NEXT: ret void
;
entry:
%LowerSrc = sext i16 %x to i32
%lo = zext i32 %LowerSrc to i64
%sign = ashr i16 %x, 15
%UpperSrc = sext i16 %sign to i32
%widen = zext i32 %UpperSrc to i64
%hi = shl nuw i64 %widen, 32
%res = or disjoint i64 %hi, %lo
store i64 %res, ptr %out, align 16
ret void
}
; ext split from i16 to i128
define void @i128_ext_split_store_i16(i16 %x, ptr %out) {
; CHECK-LABEL: define void @i128_ext_split_store_i16(
; CHECK-SAME: i16 [[X:%.*]], ptr [[OUT:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[RES:%.*]] = sext i16 [[X]] to i128
; CHECK-NEXT: store i128 [[RES]], ptr [[OUT]], align 16
; CHECK-NEXT: ret void
;
entry:
%LowerSrc = sext i16 %x to i64
%lo = zext i64 %LowerSrc to i128
%sign = ashr i16 %x, 15
%UpperSrc = sext i16 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 64
%res = or disjoint i128 %hi, %lo
store i128 %res, ptr %out, align 16
ret void
}
; negative test - wrong constant value
define i128 @i128_ext_split_neg1(i32 %x) {
; CHECK-LABEL: define i128 @i128_ext_split_neg1(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[LOWERSRC:%.*]] = sext i32 [[X]] to i64
; CHECK-NEXT: [[LO:%.*]] = zext i64 [[LOWERSRC]] to i128
; CHECK-NEXT: [[SIGN:%.*]] = ashr i32 [[X]], 31
; CHECK-NEXT: [[UPPERSRC:%.*]] = sext i32 [[SIGN]] to i64
; CHECK-NEXT: [[WIDEN:%.*]] = zext i64 [[UPPERSRC]] to i128
; CHECK-NEXT: [[HI:%.*]] = shl nuw i128 [[WIDEN]], 65
; CHECK-NEXT: [[RES:%.*]] = or disjoint i128 [[HI]], [[LO]]
; CHECK-NEXT: ret i128 [[RES]]
;
entry:
%LowerSrc = sext i32 %x to i64
%lo = zext i64 %LowerSrc to i128
%sign = ashr i32 %x, 31
%UpperSrc = sext i32 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 65
%res = or disjoint i128 %hi, %lo
ret i128 %res
}
; negative test - wrong shift value
define i128 @i128_ext_split_neg2(i32 %x) {
; CHECK-LABEL: define i128 @i128_ext_split_neg2(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[LOWERSRC:%.*]] = sext i32 [[X]] to i64
; CHECK-NEXT: [[LO:%.*]] = zext i64 [[LOWERSRC]] to i128
; CHECK-NEXT: [[SIGN:%.*]] = ashr i32 [[X]], 3
; CHECK-NEXT: [[UPPERSRC:%.*]] = sext i32 [[SIGN]] to i64
; CHECK-NEXT: [[WIDEN:%.*]] = zext i64 [[UPPERSRC]] to i128
; CHECK-NEXT: [[HI:%.*]] = shl nuw i128 [[WIDEN]], 64
; CHECK-NEXT: [[RES:%.*]] = or disjoint i128 [[HI]], [[LO]]
; CHECK-NEXT: ret i128 [[RES]]
;
entry:
%LowerSrc = sext i32 %x to i64
%lo = zext i64 %LowerSrc to i128
%sign = ashr i32 %x, 3
%UpperSrc = sext i32 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 64
%res = or disjoint i128 %hi, %lo
ret i128 %res
}
; negative test - wrong ext instruction
define i128 @i128_ext_split_neg3(i32 %x) {
; CHECK-LABEL: define i128 @i128_ext_split_neg3(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[LO:%.*]] = zext i32 [[X]] to i128
; CHECK-NEXT: [[SIGN:%.*]] = ashr i32 [[X]], 31
; CHECK-NEXT: [[UPPERSRC:%.*]] = sext i32 [[SIGN]] to i64
; CHECK-NEXT: [[WIDEN:%.*]] = zext i64 [[UPPERSRC]] to i128
; CHECK-NEXT: [[HI:%.*]] = shl nuw i128 [[WIDEN]], 64
; CHECK-NEXT: [[RES:%.*]] = or disjoint i128 [[HI]], [[LO]]
; CHECK-NEXT: ret i128 [[RES]]
;
entry:
%LowerSrc = zext i32 %x to i64
%lo = zext i64 %LowerSrc to i128
%sign = ashr i32 %x, 31
%UpperSrc = sext i32 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 64
%res = or disjoint i128 %hi, %lo
ret i128 %res
}
; negative test - wrong shift
define i128 @i128_ext_split_neg4(i32 %x) {
; CHECK-LABEL: define i128 @i128_ext_split_neg4(
; CHECK-SAME: i32 [[X:%.*]]) {
; CHECK-NEXT: [[ENTRY:.*:]]
; CHECK-NEXT: [[LOWERSRC:%.*]] = sext i32 [[X]] to i64
; CHECK-NEXT: [[LO:%.*]] = zext i64 [[LOWERSRC]] to i128
; CHECK-NEXT: [[SIGN:%.*]] = lshr i32 [[X]], 31
; CHECK-NEXT: [[WIDEN:%.*]] = zext nneg i32 [[SIGN]] to i128
; CHECK-NEXT: [[HI:%.*]] = shl nuw nsw i128 [[WIDEN]], 64
; CHECK-NEXT: [[RES:%.*]] = or disjoint i128 [[HI]], [[LO]]
; CHECK-NEXT: ret i128 [[RES]]
;
entry:
%LowerSrc = sext i32 %x to i64
%lo = zext i64 %LowerSrc to i128
%sign = lshr i32 %x, 31
%UpperSrc = sext i32 %sign to i64
%widen = zext i64 %UpperSrc to i128
%hi = shl nuw i128 %widen, 64
%res = or disjoint i128 %hi, %lo
ret i128 %res
}
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