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1; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 62; RUN: opt -passes=gvn -S < %s | FileCheck %s3;4; The Global Value Numbering pass (GVN) propagates boolean values5; that are constant in dominated basic blocks to all the uses6; in these basic blocks. However, we don't want the constant propagated7; into fake.use intrinsics since this would render the intrinsic useless8; with respect to keeping the variable live up until the fake.use.9; This test checks that we don't generate any fake.uses with constant 0.10;11; Reduced from the following test case, generated with clang -O2 -S -emit-llvm -fextend-variable-liveness test.c12;13; extern void func1();14; extern int bar();15; extern void baz(int);16;17; int foo(int i, float f, int *punused)18; {19; int j = 3*i;20; if (j > 0) {21; int m = bar(i);22; if (m) {23; char b = f;24; baz(b);25; if (b)26; goto lab;27; func1();28; }29; lab:30; func1();31; }32; return 1;33; }34 35;; GVN should propagate a constant value through to a regular call, but not to36;; a fake use, which should continue to track the original value.37 38define i32 @foo(float %f) optdebug {39; CHECK-LABEL: define i32 @foo(40; CHECK-SAME: float [[F:%.*]]) #[[ATTR0:[0-9]+]] {41; CHECK-NEXT: [[CONV:%.*]] = fptosi float [[F]] to i842; CHECK-NEXT: [[TOBOOL3:%.*]] = icmp eq i8 [[CONV]], 043; CHECK-NEXT: br i1 [[TOBOOL3]], label %[[IF_END:.*]], label %[[LAB:.*]]44; CHECK: [[IF_END]]:45; CHECK-NEXT: tail call void (...) @bees(i8 0)46; CHECK-NEXT: tail call void (...) @llvm.fake.use(i8 [[CONV]])47; CHECK-NEXT: br label %[[LAB]]48; CHECK: [[LAB]]:49; CHECK-NEXT: ret i32 150;51 %conv = fptosi float %f to i852 %tobool3 = icmp eq i8 %conv, 053 br i1 %tobool3, label %if.end, label %lab54 55if.end:56 tail call void (...) @bees(i8 %conv)57 tail call void (...) @llvm.fake.use(i8 %conv)58 br label %lab59 60lab:61 ret i32 162}63 64declare i32 @bar(...)65 66declare void @baz(i32)67 68declare void @bees(i32)69 70declare void @func1(...)71