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https://github.com/c64scene-ar/llvm-6502.git
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f6629ab847
This folds a simple loop tail into a loop latch. It covers the common (in fortran) case of postincrement loops. It's a "free" way to expose this type of loop to downstream loop optimizations that bail out on non-canonical loops (getLoopLatch is a heavily used check). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150439 91177308-0d34-0410-b5e6-96231b3b80d8
40 lines
1021 B
LLVM
40 lines
1021 B
LLVM
; RUN: opt -S < %s -loop-rotate -verify-dom-info -verify-loop-info | FileCheck %s
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; PR2624 unroll multiple exits
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@mode_table = global [4 x i32] zeroinitializer ; <[4 x i32]*> [#uses=1]
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; CHECK: @f
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; CHECK-NOT: bb4
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define i8 @f() {
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entry:
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tail call i32 @fegetround( ) ; <i32>:0 [#uses=1]
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br label %bb
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bb: ; preds = %bb4, %entry
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%mode.0 = phi i8 [ 0, %entry ], [ %indvar.next, %bb4 ] ; <i8> [#uses=4]
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zext i8 %mode.0 to i32 ; <i32>:1 [#uses=1]
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getelementptr [4 x i32]* @mode_table, i32 0, i32 %1 ; <i32*>:2 [#uses=1]
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load i32* %2, align 4 ; <i32>:3 [#uses=1]
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icmp eq i32 %3, %0 ; <i1>:4 [#uses=1]
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br i1 %4, label %bb1, label %bb2
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bb1: ; preds = %bb
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ret i8 %mode.0
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bb2: ; preds = %bb
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icmp eq i8 %mode.0, 1 ; <i1>:5 [#uses=1]
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br i1 %5, label %bb5, label %bb4
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bb4: ; preds = %bb2
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%indvar.next = add i8 %mode.0, 1 ; <i8> [#uses=1]
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br label %bb
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bb5: ; preds = %bb2
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tail call void @raise_exception( ) noreturn
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unreachable
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}
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declare i32 @fegetround()
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declare void @raise_exception() noreturn
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