ab6876a40d
Since D129288, callbr is allowed to have duplicate successors. This patch removes a limitation which prevents optimizations from actually producing such callbrs. This is probably the riskiest of all the recent callbr changes, because code with incorrect assumptions might be lurking somewhere. I fixed the one case I encountered ahead of time in8201e3ef5c. Reviewed By: nickdesaulniers Differential Revision: https://reviews.llvm.org/D129997 Originally landed as commit08860f525a("[Local] Allow creating callbr with duplicate successors") Reverted in commit1cf6b93df1("Revert "[Local] Allow creating callbr with duplicate successors"")
57 lines
1.9 KiB
LLVM
57 lines
1.9 KiB
LLVM
; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
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; RUN: opt < %s -S -jump-threading | FileCheck %s
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; This test used to cause jump threading to try to split an edge of a callbr.
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@a = global i32 0
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define i32 @c() {
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; CHECK-LABEL: @c(
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; CHECK-NEXT: entry:
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; CHECK-NEXT: [[TMP0:%.*]] = load i32, i32* @a, align 4
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; CHECK-NEXT: [[TOBOOL:%.*]] = icmp eq i32 [[TMP0]], 0
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; CHECK-NEXT: br i1 [[TOBOOL]], label [[IF_ELSE:%.*]], label [[IF_END:%.*]]
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; CHECK: if.else:
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; CHECK-NEXT: callbr void asm sideeffect "", "!i"()
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; CHECK-NEXT: to label [[IF_THEN2:%.*]] [label %if.then2]
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; CHECK: if.end:
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; CHECK-NEXT: [[CALL:%.*]] = call i32 @b()
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; CHECK-NEXT: [[PHITMP:%.*]] = icmp ne i32 [[CALL]], 0
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; CHECK-NEXT: br i1 [[PHITMP]], label [[IF_THEN2]], label [[IF_END4:%.*]]
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; CHECK: if.then2:
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; CHECK-NEXT: [[CALL3:%.*]] = call i32 @b()
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; CHECK-NEXT: br label [[IF_END4]]
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; CHECK: if.end4:
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; CHECK-NEXT: ret i32 undef
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;
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entry:
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%0 = load i32, i32* @a
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%tobool = icmp eq i32 %0, 0
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br i1 %tobool, label %if.else, label %if.then
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if.then: ; preds = %entry
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%call = call i32 @b() #2
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%phitmp = icmp ne i32 %call, 0
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br label %if.end
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if.else: ; preds = %entry
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callbr void asm sideeffect "", "!i"() #2
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to label %normal [label %if.end]
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normal: ; preds = %if.else
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br label %if.end
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if.end: ; preds = %if.else, %normal, %if.then
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%d.0 = phi i1 [ %phitmp, %if.then ], [ undef, %normal ], [ undef, %if.else ]
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br i1 %d.0, label %if.then2, label %if.end4
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if.then2: ; preds = %if.end
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%call3 = call i32 @b()
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br label %if.end4
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if.end4: ; preds = %if.then2, %if.end
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ret i32 undef
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}
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declare i32 @b()
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