Prevent ARM assembler from losing a right shift by #32 applied to a register

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159937 91177308-0d34-0410-b5e6-96231b3b80d8

2 files changed, 36 insertions, 1 deletions

diff --git a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
index b084265e5a..790125314d 100644
--- a/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
+++ b/lib/Target/ARM/AsmParser/ARMAsmParser.cpp
@@ -7247,7 +7247,9 @@ processInstruction(MCInst &Inst,
     case ARM::ADDrsi: newOpc = ARM::ADDrr; break;
     }
     // If the shift is by zero, use the non-shifted instruction definition.
-    if (ARM_AM::getSORegOffset(Inst.getOperand(3).getImm()) == 0) {
+    // The exception is for right shifts, where 0 == 32
+    if (ARM_AM::getSORegOffset(Inst.getOperand(3).getImm()) == 0 &&
+        !(SOpc == ARM_AM::lsr || SOpc == ARM_AM::asr)) {
       MCInst TmpInst;
       TmpInst.setOpcode(newOpc);
       TmpInst.addOperand(Inst.getOperand(0));
diff --git a/test/MC/ARM/basic-arm-instructions.s b/test/MC/ARM/basic-arm-instructions.s
index c62413d0ea..e682db5273 100644
--- a/test/MC/ARM/basic-arm-instructions.s
+++ b/test/MC/ARM/basic-arm-instructions.s
@@ -206,6 +206,11 @@ Lforward:
 @ CHECK: sub	r0, r0, #4              @ encoding: [0x04,0x00,0x40,0xe2]
 @ CHECK: sub	r4, r5, #21             @ encoding: [0x15,0x40,0x45,0xe2]
 
+    @ Test right shift by 32, which is encoded as 0
+    add r3, r1, r2, lsr #32
+    add r3, r1, r2, asr #32
+@ CHECK: add	r3, r1, r2, lsr #32     @ encoding: [0x22,0x30,0x81,0xe0]
+@ CHECK: add	r3, r1, r2, asr #32     @ encoding: [0x42,0x30,0x81,0xe0]
 
 @------------------------------------------------------------------------------
 @ AND
@@ -265,6 +270,12 @@ Lforward:
 @ CHECK: and	r6, r6, r7, ror r2      @ encoding: [0x77,0x62,0x06,0xe0]
 @ CHECK: and	r10, r10, r1, rrx       @ encoding: [0x61,0xa0,0x0a,0xe0]
 
+    @ Test right shift by 32, which is encoded as 0
+    and r3, r1, r2, lsr #32
+    and r3, r1, r2, asr #32
+@ CHECK: and	r3, r1, r2, lsr #32     @ encoding: [0x22,0x30,0x01,0xe0]
+@ CHECK: and	r3, r1, r2, asr #32     @ encoding: [0x42,0x30,0x01,0xe0]
+
 @------------------------------------------------------------------------------
 @ ASR
 @------------------------------------------------------------------------------
@@ -368,6 +379,12 @@ Lforward:
 @ CHECK: bic	r6, r6, r7, ror r2      @ encoding: [0x77,0x62,0xc6,0xe1]
 @ CHECK: bic	r10, r10, r1, rrx       @ encoding: [0x61,0xa0,0xca,0xe1]
 
+    @ Test right shift by 32, which is encoded as 0
+    bic r3, r1, r2, lsr #32
+    bic r3, r1, r2, asr #32
+@ CHECK: bic	r3, r1, r2, lsr #32     @ encoding: [0x22,0x30,0xc1,0xe1]
+@ CHECK: bic	r3, r1, r2, asr #32     @ encoding: [0x42,0x30,0xc1,0xe1]
+
 @------------------------------------------------------------------------------
 @ BKPT
 @------------------------------------------------------------------------------
@@ -664,6 +681,11 @@ Lforward:
 @ CHECK: eor	r6, r6, r7, ror r9      @ encoding: [0x77,0x69,0x26,0xe0]
 @ CHECK: eor	r4, r4, r5, rrx         @ encoding: [0x65,0x40,0x24,0xe0]
 
+    @ Test right shift by 32, which is encoded as 0
+    eor r3, r1, r2, lsr #32
+    eor r3, r1, r2, asr #32
+@ CHECK: eor	r3, r1, r2, lsr #32     @ encoding: [0x22,0x30,0x21,0xe0]
+@ CHECK: eor	r3, r1, r2, asr #32     @ encoding: [0x42,0x30,0x21,0xe0]
 
 @------------------------------------------------------------------------------
 @ ISB
@@ -1211,6 +1233,12 @@ Lforward:
 @ CHECK: orrslt	r6, r6, r7, ror r9      @ encoding: [0x77,0x69,0x96,0xb1]
 @ CHECK: orrsgt	r4, r4, r5, rrx         @ encoding: [0x65,0x40,0x94,0xc1]
 
+    @ Test right shift by 32, which is encoded as 0
+    orr r3, r1, r2, lsr #32
+    orr r3, r1, r2, asr #32
+@ CHECK: orr	r3, r1, r2, lsr #32     @ encoding: [0x22,0x30,0x81,0xe1]
+@ CHECK: orr	r3, r1, r2, asr #32     @ encoding: [0x42,0x30,0x81,0xe1]
+
 @------------------------------------------------------------------------------
 @ PKH
 @------------------------------------------------------------------------------
@@ -2216,6 +2244,11 @@ Lforward:
 @ CHECK: sub	r6, r6, r7, asr r9      @ encoding: [0x57,0x69,0x46,0xe0]
 @ CHECK: sub	r6, r6, r7, ror r9      @ encoding: [0x77,0x69,0x46,0xe0]
 
+    @ Test right shift by 32, which is encoded as 0
+    sub r3, r1, r2, lsr #32
+    sub r3, r1, r2, asr #32
+@ CHECK: sub	r3, r1, r2, lsr #32     @ encoding: [0x22,0x30,0x41,0xe0]
+@ CHECK: sub	r3, r1, r2, asr #32     @ encoding: [0x42,0x30,0x41,0xe0]
 
 @------------------------------------------------------------------------------
 @ SVC