llvm-6502/test/Transforms/ScalarRepl/phi-select.ll
Chris Lattner 1afcace3a3 Land the long talked about "type system rewrite" patch. This
patch brings numerous advantages to LLVM.  One way to look at it
is through diffstat:
 109 files changed, 3005 insertions(+), 5906 deletions(-)

Removing almost 3K lines of code is a good thing.  Other advantages
include:

1. Value::getType() is a simple load that can be CSE'd, not a mutating
   union-find operation.
2. Types a uniqued and never move once created, defining away PATypeHolder.
3. Structs can be "named" now, and their name is part of the identity that
   uniques them.  This means that the compiler doesn't merge them structurally
   which makes the IR much less confusing.
4. Now that there is no way to get a cycle in a type graph without a named
   struct type, "upreferences" go away.
5. Type refinement is completely gone, which should make LTO much MUCH faster
   in some common cases with C++ code.
6. Types are now generally immutable, so we can use "Type *" instead 
   "const Type *" everywhere.

Downsides of this patch are that it removes some functions from the C API,
so people using those will have to upgrade to (not yet added) new API.  
"LLVM 3.0" is the right time to do this.

There are still some cleanups pending after this, this patch is large enough
as-is.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134829 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-09 17:41:24 +00:00

154 lines
4.1 KiB
LLVM

; RUN: opt %s -scalarrepl -S | FileCheck %s
; Test promotion of allocas that have phis and select users.
target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
target triple = "x86_64-apple-darwin10.2"
%struct.X = type { i32 }
%PairTy = type {i32, i32}
; CHECK: @test1
; CHECK: %a.0 = alloca i32
; CHECK: %b.0 = alloca i32
define i32 @test1(i32 %x) nounwind readnone ssp {
entry:
%a = alloca %struct.X, align 8 ; <%struct.X*> [#uses=2]
%b = alloca %struct.X, align 8 ; <%struct.X*> [#uses=2]
%0 = getelementptr inbounds %struct.X* %a, i64 0, i32 0 ; <i32*> [#uses=1]
store i32 1, i32* %0, align 8
%1 = getelementptr inbounds %struct.X* %b, i64 0, i32 0 ; <i32*> [#uses=1]
store i32 2, i32* %1, align 8
%2 = icmp eq i32 %x, 0 ; <i1> [#uses=1]
%p.0 = select i1 %2, %struct.X* %b, %struct.X* %a ; <%struct.X*> [#uses=1]
%3 = getelementptr inbounds %struct.X* %p.0, i64 0, i32 0 ; <i32*> [#uses=1]
%4 = load i32* %3, align 8 ; <i32> [#uses=1]
ret i32 %4
}
; CHECK: @test2
; CHECK: %X.ld = phi i32 [ 1, %entry ], [ 2, %T ]
; CHECK-NEXT: ret i32 %X.ld
define i32 @test2(i1 %c) {
entry:
%A = alloca {i32, i32}
%B = getelementptr {i32, i32}* %A, i32 0, i32 0
store i32 1, i32* %B
br i1 %c, label %T, label %F
T:
%C = getelementptr {i32, i32}* %A, i32 0, i32 1
store i32 2, i32* %C
br label %F
F:
%X = phi i32* [%B, %entry], [%C, %T]
%Q = load i32* %X
ret i32 %Q
}
; CHECK: @test3
; CHECK-NEXT: %Q = select i1 %c, i32 1, i32 2
; CHECK-NEXT: ret i32 %Q
; rdar://8904039
define i32 @test3(i1 %c) {
%A = alloca {i32, i32}
%B = getelementptr {i32, i32}* %A, i32 0, i32 0
store i32 1, i32* %B
%C = getelementptr {i32, i32}* %A, i32 0, i32 1
store i32 2, i32* %C
%X = select i1 %c, i32* %B, i32* %C
%Q = load i32* %X
ret i32 %Q
}
;; We can't scalarize this, a use of the select is not an element access.
define i64 @test4(i1 %c) {
entry:
%A = alloca %PairTy
; CHECK: @test4
; CHECK: %A = alloca %PairTy
%B = getelementptr %PairTy* %A, i32 0, i32 0
store i32 1, i32* %B
%C = getelementptr %PairTy* %A, i32 0, i32 1
store i32 2, i32* %B
%X = select i1 %c, i32* %B, i32* %C
%Y = bitcast i32* %X to i64*
%Q = load i64* %Y
ret i64 %Q
}
;;
;; Tests for promoting allocas used by selects.
;; rdar://7339113
;;
define i32 @test5(i32 *%P) nounwind readnone ssp {
entry:
%b = alloca i32, align 8
store i32 2, i32* %b, align 8
;; Select on constant condition should be folded.
%p.0 = select i1 false, i32* %b, i32* %P
store i32 123, i32* %p.0
%r = load i32* %b, align 8
ret i32 %r
; CHECK: @test5
; CHECK: store i32 123, i32* %P
; CHECK: ret i32 2
}
define i32 @test6(i32 %x, i1 %c) nounwind readnone ssp {
%a = alloca i32, align 8
%b = alloca i32, align 8
store i32 1, i32* %a, align 8
store i32 2, i32* %b, align 8
%p.0 = select i1 %c, i32* %b, i32* %a
%r = load i32* %p.0, align 8
ret i32 %r
; CHECK: @test6
; CHECK-NEXT: %r = select i1 %c, i32 2, i32 1
; CHECK-NEXT: ret i32 %r
}
; Verify that the loads happen where the loads are, not where the select is.
define i32 @test7(i32 %x, i1 %c) nounwind readnone ssp {
%a = alloca i32, align 8
%b = alloca i32, align 8
store i32 1, i32* %a
store i32 2, i32* %b
%p.0 = select i1 %c, i32* %b, i32* %a
store i32 0, i32* %a
%r = load i32* %p.0, align 8
ret i32 %r
; CHECK: @test7
; CHECK-NOT: alloca i32
; CHECK: %r = select i1 %c, i32 2, i32 0
; CHECK: ret i32 %r
}
;; Promote allocs that are PHI'd together by moving the loads.
define i32 @test8(i32 %x) nounwind readnone ssp {
; CHECK: @test8
; CHECK-NOT: load i32
; CHECK-NOT: store i32
; CHECK: %p.0.ld = phi i32 [ 2, %entry ], [ 1, %T ]
; CHECK-NEXT: ret i32 %p.0.ld
entry:
%a = alloca i32, align 8
%b = alloca i32, align 8
store i32 1, i32* %a, align 8
store i32 2, i32* %b, align 8
%c = icmp eq i32 %x, 0
br i1 %c, label %T, label %Cont
T:
br label %Cont
Cont:
%p.0 = phi i32* [%b, %entry],[%a, %T]
%r = load i32* %p.0, align 8
ret i32 %r
}