[llvm] r272831 - AArch64: stop trying to use 32-bit MOVZs when expanding patchpoints.

[Tim Northover via llvm-commits]

Author: tnorthover
Date: Wed Jun 15 15:33:36 2016
New Revision: 272831

URL: http://llvm.org/viewvc/llvm-project?rev=272831&view=rev
Log:
AArch64: stop trying to use 32-bit MOVZs when expanding patchpoints.

Of course the assembly was right but because the opcode was MOVZWi it was
encoded as "movz w16, #65535, lsl #32" which is an unallocated encoding and
would go horribly wrong on a CPU.

No idea how this bug survived this long. It seems nobody is using that aspect
of patchpoints.

Modified:
    llvm/trunk/lib/Target/AArch64/AArch64AsmPrinter.cpp
    llvm/trunk/test/CodeGen/AArch64/arm64-patchpoint-webkit_jscc.ll

Modified: llvm/trunk/lib/Target/AArch64/AArch64AsmPrinter.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64AsmPrinter.cpp?rev=272831&r1=272830&r2=272831&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64AsmPrinter.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64AsmPrinter.cpp Wed Jun 15 15:33:36 2016
@@ -404,16 +404,16 @@ void AArch64AsmPrinter::LowerPATCHPOINT(
     unsigned ScratchReg = MI.getOperand(Opers.getNextScratchIdx()).getReg();
     EncodedBytes = 16;
     // Materialize the jump address:
-    EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVZWi)
+    EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVZXi)
                                     .addReg(ScratchReg)
                                     .addImm((CallTarget >> 32) & 0xFFFF)
                                     .addImm(32));
-    EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKWi)
+    EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
                                     .addReg(ScratchReg)
                                     .addReg(ScratchReg)
                                     .addImm((CallTarget >> 16) & 0xFFFF)
                                     .addImm(16));
-    EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKWi)
+    EmitToStreamer(OutStreamer, MCInstBuilder(AArch64::MOVKXi)
                                     .addReg(ScratchReg)
                                     .addReg(ScratchReg)
                                     .addImm(CallTarget & 0xFFFF)

Modified: llvm/trunk/test/CodeGen/AArch64/arm64-patchpoint-webkit_jscc.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/AArch64/arm64-patchpoint-webkit_jscc.ll?rev=272831&r1=272830&r2=272831&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/AArch64/arm64-patchpoint-webkit_jscc.ll (original)
+++ llvm/trunk/test/CodeGen/AArch64/arm64-patchpoint-webkit_jscc.ll Wed Jun 15 15:33:36 2016
@@ -1,5 +1,12 @@
-; RUN: llc -mtriple=arm64-apple-darwin -enable-misched=0 -mcpu=cyclone            < %s | FileCheck %s
+; RUN: llc -mtriple=arm64-apple-darwin -enable-misched=0 -mcpu=cyclone < %s | FileCheck %s
 ; RUN: llc -mtriple=arm64-apple-darwin -enable-misched=0 -mcpu=cyclone -fast-isel < %s | FileCheck %s --check-prefix=FAST
+; RUN: llc -mtriple=arm64-apple-darwin -enable-misched=0 -mcpu=cyclone -filetype=obj -o %t %s
+; RUN: llvm-objdump -triple arm64-apple-darwin -d %t | FileCheck %s --check-prefix CHECK-ENCODING
+
+; CHECK-ENCODING-NOT: <unknown>
+; CHECK-ENCODING: movz x16, #65535, lsl #32
+; CHECK-ENCODING: movk x16, #57005, lsl #16
+; CHECK-ENCODING: movk x16, #48879
 
 ; One argument will be passed in register, the other will be pushed on the stack.
 ; Return value in x0.
@@ -11,8 +18,8 @@ entry:
 ; CHECK-NEXT:  mov  x0, x{{.+}}
 ; CHECK:       Ltmp
 ; CHECK-NEXT:  movz  x16, #65535, lsl #32
-; CHECK-NEXT:  movk  x16, #57005, lsl #16
-; CHECK-NEXT:  movk  x16, #48879
+; CHECK:  movk  x16, #57005, lsl #16
+; CHECK:  movk  x16, #48879
 ; CHECK-NEXT:  blr x16
 ; FAST-LABEL:  jscall_patchpoint_codegen:
 ; FAST:        Ltmp