[llvm-branch-commits] [llvm] f3e1d94 - [ARM][atomicrmw] Fix CMP_SWAP_32 expand assert

[Tom Stellard via llvm-branch-commits]

Author: Tomas Matheson
Date: 2021-08-18T12:14:24-07:00
New Revision: f3e1d94de69dda09e7334ce38eacfa0989cd7358

URL: https://github.com/llvm/llvm-project/commit/f3e1d94de69dda09e7334ce38eacfa0989cd7358
DIFF: https://github.com/llvm/llvm-project/commit/f3e1d94de69dda09e7334ce38eacfa0989cd7358.diff

LOG: [ARM][atomicrmw] Fix CMP_SWAP_32 expand assert

This assert is intended to ensure that the high registers are not
selected when it is passed to one of the thumb UXT instructions. However
it was triggering even for 32 bit where no UXT instruction is emitted.

Fixes PR51313.

Differential Revision: https://reviews.llvm.org/D107363

(cherry picked from commit 40650f27b5df95b2f96d25ea03976d8136804441)

Added: 
    

Modified: 
    llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
    llvm/test/CodeGen/ARM/cmpxchg.mir

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp b/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
index 2167ad5d74676..e68a3aa8bf478 100644
--- a/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
+++ b/llvm/lib/Target/ARM/ARMExpandPseudoInsts.cpp
@@ -1647,7 +1647,7 @@ bool ARMExpandPseudo::ExpandCMP_SWAP(MachineBasicBlock &MBB,
            "CMP_SWAP not expected to be custom expanded for Thumb1");
     assert((UxtOp == 0 || UxtOp == ARM::tUXTB || UxtOp == ARM::tUXTH) &&
            "ARMv8-M.baseline does not have t2UXTB/t2UXTH");
-    assert(ARM::tGPRRegClass.contains(DesiredReg) &&
+    assert((UxtOp == 0 || ARM::tGPRRegClass.contains(DesiredReg)) &&
            "DesiredReg used for UXT op must be tGPR");
   }
 

diff  --git a/llvm/test/CodeGen/ARM/cmpxchg.mir b/llvm/test/CodeGen/ARM/cmpxchg.mir
index 1b88dcdd7b2c4..dd640457fb0b1 100644
--- a/llvm/test/CodeGen/ARM/cmpxchg.mir
+++ b/llvm/test/CodeGen/ARM/cmpxchg.mir
@@ -1,5 +1,6 @@
 # NOTE: Assertions have been autogenerated by utils/update_mir_test_checks.py
 # RUN: llc -o - %s -mtriple=armv7-unknown-linux-gnu -verify-machineinstrs -run-pass=arm-pseudo | FileCheck %s
+# RUN: llc -o - %s -mtriple=thumbv7-unknown-linux-gnu -verify-machineinstrs -run-pass=arm-pseudo | FileCheck %s --check-prefix=THUMB
 ---
 name: func
 tracksRegLiveness: true
@@ -23,5 +24,62 @@ body: |
     ; CHECK: CMPri killed $r2, 0, 14 /* CC::al */, $noreg, implicit-def $cpsr
     ; CHECK: Bcc %bb.1, 1 /* CC::ne */, killed $cpsr
     ; CHECK: .3:
+    ; THUMB-LABEL: name: func
+    ; THUMB: successors: %bb.1(0x80000000)
+    ; THUMB: liveins: $r0_r1, $r4_r5, $r3, $lr
+    ; THUMB: .1:
+    ; THUMB: successors: %bb.3(0x40000000), %bb.2(0x40000000)
+    ; THUMB: liveins: $r4, $r5, $r3
+    ; THUMB: $r0, $r1 = t2LDREXD $r3, 14 /* CC::al */, $noreg
+    ; THUMB: tCMPhir killed $r0, $r4, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    ; THUMB: tCMPhir killed $r1, $r5, 0 /* CC::eq */, killed $cpsr, implicit-def $cpsr
+    ; THUMB: tBcc %bb.3, 1 /* CC::ne */, killed $cpsr
+    ; THUMB: .2:
+    ; THUMB: successors: %bb.1(0x40000000), %bb.3(0x40000000)
+    ; THUMB: liveins: $r4, $r5, $r3
+    ; THUMB: early-clobber $r2 = t2STREXD $r4, $r5, $r3, 14 /* CC::al */, $noreg
+    ; THUMB: t2CMPri killed $r2, 0, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    ; THUMB: tBcc %bb.1, 1 /* CC::ne */, killed $cpsr
+    ; THUMB: .3:
     dead early-clobber renamable $r0_r1, dead early-clobber renamable $r2 = CMP_SWAP_64 killed renamable $r3, killed renamable $r4_r5, renamable $r4_r5 :: (volatile load store monotonic monotonic (s64))
 ...
+---
+name: func2
+tracksRegLiveness: true
+body: |
+  bb.0:
+    liveins: $r1, $r2, $r3, $r12, $lr
+    ; CHECK-LABEL: name: func2
+    ; CHECK: successors: %bb.1(0x80000000)
+    ; CHECK: liveins: $r1, $r2, $r3, $r12, $lr
+    ; CHECK: .1:
+    ; CHECK: successors: %bb.3(0x40000000), %bb.2(0x40000000)
+    ; CHECK: liveins: $lr, $r3, $r12
+    ; CHECK: $r1 = LDREX $r3, 14 /* CC::al */, $noreg
+    ; CHECK: CMPrr killed $r1, $r12, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    ; CHECK: Bcc %bb.3, 1 /* CC::ne */, killed $cpsr
+    ; CHECK: .2:
+    ; CHECK: successors: %bb.1(0x40000000), %bb.3(0x40000000)
+    ; CHECK: liveins: $lr, $r3, $r12
+    ; CHECK: early-clobber $r2 = STREX $lr, $r3, 14 /* CC::al */, $noreg
+    ; CHECK: CMPri killed $r2, 0, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    ; CHECK: Bcc %bb.1, 1 /* CC::ne */, killed $cpsr
+    ; CHECK: .3:
+    ; THUMB-LABEL: name: func2
+    ; THUMB: successors: %bb.1(0x80000000)
+    ; THUMB: liveins: $r1, $r2, $r3, $r12, $lr
+    ; THUMB: .1:
+    ; THUMB: successors: %bb.3(0x40000000), %bb.2(0x40000000)
+    ; THUMB: liveins: $lr, $r3, $r12
+    ; THUMB: $r1 = t2LDREX $r3, 0, 14 /* CC::al */, $noreg
+    ; THUMB: tCMPhir killed $r1, $r12, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    ; THUMB: tBcc %bb.3, 1 /* CC::ne */, killed $cpsr
+    ; THUMB: .2:
+    ; THUMB: successors: %bb.1(0x40000000), %bb.3(0x40000000)
+    ; THUMB: liveins: $lr, $r3, $r12
+    ; THUMB: early-clobber $r2 = t2STREX $lr, $r3, 0, 14 /* CC::al */, $noreg
+    ; THUMB: t2CMPri killed $r2, 0, 14 /* CC::al */, $noreg, implicit-def $cpsr
+    ; THUMB: tBcc %bb.1, 1 /* CC::ne */, killed $cpsr
+    ; THUMB: .3:
+    dead early-clobber renamable $r1, dead early-clobber renamable $r2 = CMP_SWAP_32 killed renamable $r3, killed renamable $r12, killed renamable $lr
+...