It's not legal to fold a load from a narrower stack slot into a wider instruction. If done, the instruction does a 64-bit load and that's not

safe. This can happen we a subreg_to_reg 0 has been coalesced. One
exception is when the instruction that folds the load is a move, then we
can simply turn it into a 32-bit load from the stack slot.                                                                                                                    

rdar://7170444


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@81494 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 48 insertions, 0 deletions

diff --git a/test/CodeGen/X86/2009-09-10-LoadFoldingBug.ll b/test/CodeGen/X86/2009-09-10-LoadFoldingBug.ll
new file mode 100644
index 0000000000..df52949701
--- /dev/null
+++ b/test/CodeGen/X86/2009-09-10-LoadFoldingBug.ll
@@ -0,0 +1,48 @@
+; RUN: llc < %s -mtriple=x86_64-apple-darwin10.0 -relocation-model=pic -disable-fp-elim | FileCheck %s
+
+; It's not legal to fold a load from 32-bit stack slot into a 64-bit
+; instruction. If done, the instruction does a 64-bit load and that's not
+; safe. This can happen we a subreg_to_reg 0 has been coalesced. One
+; exception is when the instruction that folds the load is a move, then we
+; can simply turn it into a 32-bit load from the stack slot.
+; rdar://7170444
+
+%struct.ComplexType = type { i32 }
+
+define i32 @t(i32 %clientPort, i32 %pluginID, i32 %requestID, i32 %objectID, i64 %serverIdentifier, i64 %argumentsData, i32 %argumentsLength) ssp {
+entry:
+; CHECK: _t:
+; CHECK: movl 16(%rbp),
+; CHECK: movl 16(%rbp),
+  %0 = zext i32 %argumentsLength to i64           ; <i64> [#uses=1]
+  %1 = zext i32 %clientPort to i64                ; <i64> [#uses=1]
+  %2 = inttoptr i64 %1 to %struct.ComplexType*    ; <%struct.ComplexType*> [#uses=1]
+  %3 = invoke i8* @pluginInstance(i8* undef, i32 %pluginID)
+          to label %invcont unwind label %lpad    ; <i8*> [#uses=1]
+
+invcont:                                          ; preds = %entry
+  %4 = add i32 %requestID, %pluginID              ; <i32> [#uses=0]
+  %5 = invoke zeroext i8 @invoke(i8* %3, i32 %objectID, i8* undef, i64 %argumentsData, i32 %argumentsLength, i64* undef, i32* undef)
+          to label %invcont1 unwind label %lpad   ; <i8> [#uses=0]
+
+invcont1:                                         ; preds = %invcont
+  %6 = getelementptr inbounds %struct.ComplexType* %2, i64 0, i32 0 ; <i32*> [#uses=1]
+  %7 = load i32* %6, align 4                      ; <i32> [#uses=1]
+  invoke void @booleanAndDataReply(i32 %7, i32 undef, i32 %requestID, i32 undef, i64 undef, i32 undef)
+          to label %invcont2 unwind label %lpad
+
+invcont2:                                         ; preds = %invcont1
+  ret i32 0
+
+lpad:                                             ; preds = %invcont1, %invcont, %entry
+  %8 = call i32 @vm_deallocate(i32 undef, i64 0, i64 %0) ; <i32> [#uses=0]
+  unreachable
+}
+
+declare i32 @vm_deallocate(i32, i64, i64)
+
+declare i8* @pluginInstance(i8*, i32)
+
+declare zeroext i8 @invoke(i8*, i32, i8*, i64, i32, i64*, i32*)
+
+declare void @booleanAndDataReply(i32, i32, i32, i32, i64, i32)