[PowerPC ][NFC] Add a test case for the function atomic_compare_exchange_weak (#141263)

Add test case to test the generated asm of the function
atomic_compare_exchange_weak

Author: diggerlin

llvm/test/CodeGen/PowerPC/atomic-compare-exchange-weak.ll

@@ -0,0 +1,102 @@
+; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 5
+; Test the generation of asm for the function:
+; int foo(_Atomic int *cp, int *old, int c) {
+;  return atomic_compare_exchange_weak_explicit(cp, old, c, __ATOMIC_RELAXED, __ATOMIC_RELAXED);
+; }
+
+; RUN: llc < %s -ppc-asm-full-reg-names  -mtriple=powerpc-ibm-aix -mcpu=pwr8  -verify-machineinstrs |\ 
+;        FileCheck %s --check-prefix=CHECK
+; RUN: llc < %s -ppc-asm-full-reg-names  -mtriple=powerpc64-ibm-aix -mcpu=pwr8  -verify-machineinstrs |\
+;        FileCheck %s --check-prefix=CHECK64
+
+define i32 @foo(ptr noundef %cp, ptr noundef %old, i32 noundef %c)  {
+; CHECK-LABEL: foo:
+; CHECK:       # %bb.0: # %entry
+; CHECK-NEXT:    lwz r7, 0(r4)
+; CHECK-NEXT:    stw r3, -4(r1)
+; CHECK-NEXT:    stw r4, -8(r1)
+; CHECK-NEXT:    stw r5, -12(r1)
+; CHECK-NEXT:    stw r5, -16(r1)
+; CHECK-NEXT:  L..BB0_1: # %entry
+; CHECK-NEXT:    #
+; CHECK-NEXT:    lwarx r6, 0, r3
+; CHECK-NEXT:    cmpw cr1, r6, r7
+; CHECK-NEXT:    bne cr1, L..BB0_3
+; CHECK-NEXT:  # %bb.2: # %entry
+; CHECK-NEXT:    #
+; CHECK-NEXT:    stwcx. r5, 0, r3
+; CHECK-NEXT:    bne cr0, L..BB0_1
+; CHECK-NEXT:  L..BB0_3: # %entry
+; CHECK-NEXT:    cmplw r6, r7
+; CHECK-NEXT:    beq cr0, L..BB0_5
+; CHECK-NEXT:  # %bb.4: # %cmpxchg.store_expected
+; CHECK-NEXT:    stw r6, 0(r4)
+; CHECK-NEXT:  L..BB0_5: # %cmpxchg.continue
+; CHECK-NEXT:    li r3, 0
+; CHECK-NEXT:    li r4, 1
+; CHECK-NEXT:    isel r3, r4, r3, 4*cr1+eq
+; CHECK-NEXT:    stb r3, -17(r1)
+; CHECK-NEXT:    blr
+;
+; CHECK64-LABEL: foo:
+; CHECK64:       # %bb.0: # %entry
+; CHECK64-NEXT:    lwz r7, 0(r4)
+; CHECK64-NEXT:    std r3, -8(r1)
+; CHECK64-NEXT:    std r4, -16(r1)
+; CHECK64-NEXT:    stw r5, -20(r1)
+; CHECK64-NEXT:    stw r5, -24(r1)
+; CHECK64-NEXT:  L..BB0_1: # %entry
+; CHECK64-NEXT:    #
+; CHECK64-NEXT:    lwarx r6, 0, r3
+; CHECK64-NEXT:    cmpw cr1, r6, r7
+; CHECK64-NEXT:    bne cr1, L..BB0_3
+; CHECK64-NEXT:  # %bb.2: # %entry
+; CHECK64-NEXT:    #
+; CHECK64-NEXT:    stwcx. r5, 0, r3
+; CHECK64-NEXT:    bne cr0, L..BB0_1
+; CHECK64-NEXT:  L..BB0_3: # %entry
+; CHECK64-NEXT:    cmplw r6, r7
+; CHECK64-NEXT:    beq cr0, L..BB0_5
+; CHECK64-NEXT:  # %bb.4: # %cmpxchg.store_expected
+; CHECK64-NEXT:    stw r6, 0(r4)
+; CHECK64-NEXT:  L..BB0_5: # %cmpxchg.continue
+; CHECK64-NEXT:    li r3, 0
+; CHECK64-NEXT:    li r4, 1
+; CHECK64-NEXT:    isel r3, r4, r3, 4*cr1+eq
+; CHECK64-NEXT:    li r4, 1
+; CHECK64-NEXT:    stb r3, -25(r1)
+; CHECK64-NEXT:    li r3, 0
+; CHECK64-NEXT:    isel r3, r4, r3, 4*cr1+eq
+; CHECK64-NEXT:    blr
+entry:
+  %cp.addr = alloca ptr, align 4
+  %old.addr = alloca ptr, align 4
+  %c.addr = alloca i32, align 4
+  %.atomictmp = alloca i32, align 4
+  %cmpxchg.bool = alloca i8, align 1
+  store ptr %cp, ptr %cp.addr, align 4
+  store ptr %old, ptr %old.addr, align 4
+  store i32 %c, ptr %c.addr, align 4
+  %0 = load ptr, ptr %cp.addr, align 4
+  %1 = load ptr, ptr %old.addr, align 4
+  %2 = load i32, ptr %c.addr, align 4
+  store i32 %2, ptr %.atomictmp, align 4
+  %3 = load i32, ptr %1, align 4
+  %4 = load i32, ptr %.atomictmp, align 4
+  %5 = cmpxchg weak ptr %0, i32 %3, i32 %4 monotonic monotonic, align 4
+  %6 = extractvalue { i32, i1 } %5, 0
+  %7 = extractvalue { i32, i1 } %5, 1
+  br i1 %7, label %cmpxchg.continue, label %cmpxchg.store_expected
+
+cmpxchg.store_expected:                           ; preds = %entry
+  store i32 %6, ptr %1, align 4
+  br label %cmpxchg.continue
+
+cmpxchg.continue:                                 ; preds = %cmpxchg.store_expected, %entry
+  %storedv = zext i1 %7 to i8
+  store i8 %storedv, ptr %cmpxchg.bool, align 1
+  %8 = load i8, ptr %cmpxchg.bool, align 1
+  %loadedv = trunc i8 %8 to i1
+  %conv = zext i1 %loadedv to i32
+  ret i32 %conv
+}