[llvm] 79b55e5 - [GVN] Fix test for loop load PRE on alloca (NFC)

[Nikita Popov via llvm-commits]

Author: Nikita Popov
Date: 2021-08-22T22:28:53+02:00
New Revision: 79b55e5038324e61a3abf4e6a9a949c473edd858

URL: https://github.com/llvm/llvm-project/commit/79b55e5038324e61a3abf4e6a9a949c473edd858
DIFF: https://github.com/llvm/llvm-project/commit/79b55e5038324e61a3abf4e6a9a949c473edd858.diff

LOG: [GVN] Fix test for loop load PRE on alloca (NFC)

This test was not modifying the pointer in the loop, so the loads
just ended up as undef, without relation to loop load PRE.

Pass the alloca to the called function, so the memory is
potentially modified.

Added: 
    

Modified: 
    llvm/test/Transforms/GVN/PRE/pre-loop-load.ll

Removed: 
    


################################################################################
diff  --git a/llvm/test/Transforms/GVN/PRE/pre-loop-load.ll b/llvm/test/Transforms/GVN/PRE/pre-loop-load.ll
index 8ca12284d5c42..a94269c548b8c 100644
--- a/llvm/test/Transforms/GVN/PRE/pre-loop-load.ll
+++ b/llvm/test/Transforms/GVN/PRE/pre-loop-load.ll
@@ -202,31 +202,36 @@ exit:
   ret i32 %x
 }
 
+declare void @may_modify_or_free_pointer(i32* %p)
+
 ; TODO: Despite the fact that the function may free memory in general, it
 ; cannot free memory allocated by alloca.
 define i32 @test_load_on_cold_path_may_free_memory_alloca() {
 ; CHECK-LABEL: @test_load_on_cold_path_may_free_memory_alloca(
 ; CHECK-NEXT:  entry:
 ; CHECK-NEXT:    [[P:%.*]] = alloca i32, align 4
-; CHECK-NEXT:    call void @may_free_memory()
+; CHECK-NEXT:    call void @may_modify_or_free_pointer(i32* [[P]])
 ; CHECK-NEXT:    br label [[LOOP:%.*]]
 ; CHECK:       loop:
-; CHECK-NEXT:    br i1 undef, label [[HOT_PATH:%.*]], label [[COLD_PATH:%.*]]
+; CHECK-NEXT:    [[IV:%.*]] = phi i32 [ 0, [[ENTRY:%.*]] ], [ [[IV_NEXT:%.*]], [[BACKEDGE:%.*]] ]
+; CHECK-NEXT:    [[X:%.*]] = load i32, i32* [[P]], align 4
+; CHECK-NEXT:    [[COND:%.*]] = icmp ne i32 [[X]], 0
+; CHECK-NEXT:    br i1 [[COND]], label [[HOT_PATH:%.*]], label [[COLD_PATH:%.*]]
 ; CHECK:       hot_path:
-; CHECK-NEXT:    br label [[BACKEDGE:%.*]]
+; CHECK-NEXT:    br label [[BACKEDGE]]
 ; CHECK:       cold_path:
-; CHECK-NEXT:    call void @may_free_memory()
+; CHECK-NEXT:    call void @may_modify_or_free_pointer(i32* [[P]])
 ; CHECK-NEXT:    br label [[BACKEDGE]]
 ; CHECK:       backedge:
-; CHECK-NEXT:    br i1 false, label [[BACKEDGE_LOOP_CRIT_EDGE:%.*]], label [[EXIT:%.*]]
-; CHECK:       backedge.loop_crit_edge:
-; CHECK-NEXT:    br label [[LOOP]]
+; CHECK-NEXT:    [[IV_NEXT]] = add i32 [[IV]], [[X]]
+; CHECK-NEXT:    [[LOOP_COND:%.*]] = icmp ult i32 [[IV_NEXT]], 1000
+; CHECK-NEXT:    br i1 [[LOOP_COND]], label [[LOOP]], label [[EXIT:%.*]]
 ; CHECK:       exit:
-; CHECK-NEXT:    ret i32 undef
+; CHECK-NEXT:    ret i32 [[X]]
 ;
 entry:
   %p = alloca i32
-  call void @may_free_memory()
+  call void @may_modify_or_free_pointer(i32* %p)
   br label %loop
 
 loop:
@@ -239,7 +244,7 @@ hot_path:
   br label %backedge
 
 cold_path:
-  call void @may_free_memory()
+  call void @may_modify_or_free_pointer(i32* %p)
   br label %backedge
 
 backedge: