[NFC][InstCombine] Add test with non-CSE'd casts of load

in @t0 we can still change type of load and get rid of casts.

Author: LebedevRI

llvm/test/Transforms/InstCombine/multi-use-load-casts.ll

@@ -0,0 +1,153 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
+; RUN: opt -S -instcombine < %s | FileCheck %s
+
+target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+
+; Positive test - all uses are identical casts.
+define void @t0(i1 zeroext %c0, i1 zeroext %c1, i64* nocapture readonly %src) {
+; CHECK-LABEL: @t0(
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[DATA:%.*]] = load i64, i64* [[SRC:%.*]], align 8
+; CHECK-NEXT:    br i1 [[C0:%.*]], label [[BB3:%.*]], label [[BB7:%.*]]
+; CHECK:       bb3:
+; CHECK-NEXT:    br i1 [[C1:%.*]], label [[BB4:%.*]], label [[BB5:%.*]]
+; CHECK:       bb4:
+; CHECK-NEXT:    tail call void @abort()
+; CHECK-NEXT:    unreachable
+; CHECK:       bb5:
+; CHECK-NEXT:    [[PTR0:%.*]] = inttoptr i64 [[DATA]] to i32*
+; CHECK-NEXT:    tail call void @sink0(i32* [[PTR0]])
+; CHECK-NEXT:    br label [[BB9:%.*]]
+; CHECK:       bb7:
+; CHECK-NEXT:    [[PTR1:%.*]] = inttoptr i64 [[DATA]] to i32*
+; CHECK-NEXT:    tail call void @sink1(i32* [[PTR1]])
+; CHECK-NEXT:    br label [[BB9]]
+; CHECK:       bb9:
+; CHECK-NEXT:    ret void
+;
+bb:
+  %data = load i64, i64* %src, align 8
+  br i1 %c0, label %bb3, label %bb7
+
+bb3:
+  br i1 %c1, label %bb4, label %bb5
+
+bb4:
+  tail call void @abort()
+  unreachable
+
+bb5:
+  %ptr0 = inttoptr i64 %data to i32*
+  tail call void @sink0(i32* %ptr0)
+  br label %bb9
+
+bb7:
+  %ptr1 = inttoptr i64 %data to i32*
+  tail call void @sink1(i32* %ptr1)
+  br label %bb9
+
+bb9:
+  ret void
+}
+
+; Negative test - all uses are casts, but non-identical ones.
+define void @n1(i1 zeroext %c0, i1 zeroext %c1, i64* nocapture readonly %src) {
+; CHECK-LABEL: @n1(
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[DATA:%.*]] = load i64, i64* [[SRC:%.*]], align 8
+; CHECK-NEXT:    br i1 [[C0:%.*]], label [[BB3:%.*]], label [[BB7:%.*]]
+; CHECK:       bb3:
+; CHECK-NEXT:    br i1 [[C1:%.*]], label [[BB4:%.*]], label [[BB5:%.*]]
+; CHECK:       bb4:
+; CHECK-NEXT:    tail call void @abort()
+; CHECK-NEXT:    unreachable
+; CHECK:       bb5:
+; CHECK-NEXT:    [[PTR0:%.*]] = inttoptr i64 [[DATA]] to i32*
+; CHECK-NEXT:    tail call void @sink0(i32* [[PTR0]])
+; CHECK-NEXT:    br label [[BB9:%.*]]
+; CHECK:       bb7:
+; CHECK-NEXT:    [[VEC:%.*]] = bitcast i64 [[DATA]] to <2 x i32>
+; CHECK-NEXT:    tail call void @sink2(<2 x i32> [[VEC]])
+; CHECK-NEXT:    br label [[BB9]]
+; CHECK:       bb9:
+; CHECK-NEXT:    ret void
+;
+bb:
+  %data = load i64, i64* %src, align 8
+  br i1 %c0, label %bb3, label %bb7
+
+bb3:
+  br i1 %c1, label %bb4, label %bb5
+
+bb4:
+  tail call void @abort()
+  unreachable
+
+bb5:
+  %ptr0 = inttoptr i64 %data to i32*
+  tail call void @sink0(i32* %ptr0)
+  br label %bb9
+
+bb7:
+  %vec = bitcast i64 %data to <2 x i32> ; different cast
+  tail call void @sink2(<2 x i32> %vec)
+  br label %bb9
+
+bb9:
+  ret void
+}
+
+; Negative test - have non-cast users.
+define void @n2(i1 zeroext %c0, i1 zeroext %c1, i64* nocapture readonly %src) {
+; CHECK-LABEL: @n2(
+; CHECK-NEXT:  bb:
+; CHECK-NEXT:    [[DATA:%.*]] = load i64, i64* [[SRC:%.*]], align 8
+; CHECK-NEXT:    br i1 [[C0:%.*]], label [[BB3:%.*]], label [[BB7:%.*]]
+; CHECK:       bb3:
+; CHECK-NEXT:    br i1 [[C1:%.*]], label [[BB4:%.*]], label [[BB5:%.*]]
+; CHECK:       bb4:
+; CHECK-NEXT:    tail call void @abort()
+; CHECK-NEXT:    unreachable
+; CHECK:       bb5:
+; CHECK-NEXT:    [[PTR0:%.*]] = inttoptr i64 [[DATA]] to i32*
+; CHECK-NEXT:    tail call void @sink0(i32* [[PTR0]])
+; CHECK-NEXT:    br label [[BB9:%.*]]
+; CHECK:       bb7:
+; CHECK-NEXT:    tail call void @sink3(i64 [[DATA]])
+; CHECK-NEXT:    br label [[BB9]]
+; CHECK:       bb9:
+; CHECK-NEXT:    ret void
+;
+bb:
+  %data = load i64, i64* %src, align 8
+  br i1 %c0, label %bb3, label %bb7
+
+bb3:
+  br i1 %c1, label %bb4, label %bb5
+
+bb4:
+  tail call void @abort()
+  unreachable
+
+bb5:
+  %ptr0 = inttoptr i64 %data to i32*
+  tail call void @sink0(i32* %ptr0)
+  br label %bb9
+
+bb7:
+  tail call void @sink3(i64 %data) ; non-cast use
+  br label %bb9
+
+bb9:
+  ret void
+}
+
+declare void @abort()
+
+declare void @sink0(i32*)
+
+declare void @sink1(i32*)
+
+declare void @sink2(<2 x i32>)
+
+declare void @sink3(i64)