diff --git a/gdb/aarch64-tdep.c b/gdb/aarch64-tdep.c
index 673815c2..0cce4072 100644
--- a/gdb/aarch64-tdep.c
+++ b/gdb/aarch64-tdep.c
@@ -5812,6 +5812,93 @@ aarch64_record_load_store (aarch64_insn_decode_record *aarch64_insn_r)
aarch64_insn_r->reg_rec_count = 1;
}
}
+ /* LRCPC3 instructions. This covers ldiapp/stilp, ldapur/stlur (FP/SIMD),
+ ldapr/stlr. */
+ else if ((insn_bits24_27 & 0x0b) == 0x09 && insn_bits28_29 == 0x01
+ && insn_bits10_11 == 0x02 && !insn_bit21)
+ {
+ /* ldapur/stlur (FP/SIMD), ldapr/stlr. We can differentiate between the
+ 2 types by checking the vector flag. */
+ if (insn_bit23 || vector_flag)
+ {
+ /* For the vector instruction, the offset comes from the imm9
+ bitfield, whereas the other can only take possible values from the
+ size bitfield. */
+ int16_t imm9_off = sbits (aarch64_insn_r->aarch64_insn, 12, 20);
+ offset = vector_flag ? imm9_off : -(1 << size_bits);
+ uint32_t regnum_offset = vector_flag ? AARCH64_V0_REGNUM : 0;
+ if (ld_flag)
+ {
+ record_buf[0] = reg_rt + regnum_offset;
+ aarch64_insn_r->reg_rec_count = 1;
+ if (!vector_flag)
+ {
+ /* The Rn register always has writeback in LRCPC3. This is
+ not the case in LRCPC. */
+ record_buf[1] = reg_rn;
+ aarch64_insn_r->reg_rec_count = 2;
+ }
+ }
+ else
+ {
+ regcache_raw_read_unsigned (aarch64_insn_r->regcache, reg_rn,
+ &address);
+ /* (vector_flag && insn_bit23) is the STLUR instruction with Q
+ register. */
+ datasize = (vector_flag && insn_bit23) ? 128 : (8 << size_bits);
+ /* LRCPC3 adds STLR with a pre-indexed offset. There is another
+ STLR variant without offset but this has a different encoding. */
+ if (!vector_flag)
+ {
+ record_buf[0] = reg_rn;
+ aarch64_insn_r->reg_rec_count = 1;
+ }
+ record_buf_mem[0] = datasize >> 3;
+ record_buf_mem[1] = address + offset;
+ aarch64_insn_r->mem_rec_count = 1;
+ }
+ }
+ else
+ {
+ /* ldiapp/stilp. */
+ uint8_t opc2 = bits (aarch64_insn_r->aarch64_insn, 12, 15);
+ reg_rt2 = bits (aarch64_insn_r->aarch64_insn, 16, 20);
+ if (ld_flag)
+ {
+ record_buf[0] = reg_rt;
+ record_buf[1] = reg_rt2;
+ aarch64_insn_r->reg_rec_count = 2;
+
+ /* If the registers don't match and there's no offset then
+ there's WB. */
+ if (reg_rn != reg_rt && reg_rn != reg_rt2 && opc2 == 0)
+ {
+ record_buf[2] = reg_rn;
+ aarch64_insn_r->reg_rec_count = 3;
+ }
+ }
+ else
+ {
+ datasize = 8 << size_bits;
+ regcache_raw_read_unsigned (aarch64_insn_r->regcache, reg_rn,
+ &address);
+ offset = (opc2 == 0) ? (2 << size_bits) : 0;
+ address -= offset;
+
+ record_buf_mem[0] = datasize >> 3;
+ record_buf_mem[1] = address;
+ record_buf_mem[2] = datasize >> 3;
+ record_buf_mem[3] = address + (datasize >> 3);
+ aarch64_insn_r->mem_rec_count = 2;
+
+ if (offset != 0)
+ {
+ record_buf[0] = reg_rn;
+ aarch64_insn_r->reg_rec_count = 1;
+ }
+ }
+ }
+ }
/* Load/store register (register offset) instructions. */
else if ((insn_bits24_27 & 0x0b) == 0x08 && insn_bits28_29 == 0x03
&& insn_bits10_11 == 0x02 && insn_bit21)
diff --git a/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.c b/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.c
new file mode 100644
index 00000000..d61d3239
--- /dev/null
+++ b/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.c
@@ -0,0 +1,216 @@
+/* This test program is part of GDB, the GNU debugger.
+
+ Copyright 2024-2026 Free Software Foundation, Inc.
+
+ This program is free software; you can redistribute it and/or modify
+ it under the terms of the GNU General Public License as published by
+ the Free Software Foundation; either version 3 of the License, or
+ (at your option) any later version.
+
+ This program is distributed in the hope that it will be useful,
+ but WITHOUT ANY WARRANTY; without even the implied warranty of
+ MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+ GNU General Public License for more details.
+
+ You should have received a copy of the GNU General Public License
+ along with this program. If not, see . */
+
+#include
+#include
+#include
+
+#define INITIAL_STRING "This is just some string."
+#define BUF_SIZE sizeof (INITIAL_STRING)
+
+#define PREPARE_SRC_AND_PTR(OFFSET) \
+ strcpy (src, INITIAL_STRING); \
+ __asm__ volatile ("mov x21, %0" \
+ : \
+ : "r"((uint64_t *)((uint8_t *)src + (OFFSET))) \
+ : "x21")
+
+#define PREPARE_GPR(OFFSET) \
+ __asm__ volatile ("mov x19, #0\n" ::: "x19"); \
+ __asm__ volatile ("mov x20, #0\n" ::: "x20"); \
+ PREPARE_SRC_AND_PTR (OFFSET)
+
+#define PREPARE_VECTOR_REG(OFFSET) \
+ __asm__ volatile ("movi v22.2d, #0\n" ::: "v22"); \
+ PREPARE_SRC_AND_PTR (OFFSET)
+
+int
+main (void)
+{
+ alignas (16) char src[BUF_SIZE];
+
+ PREPARE_GPR (0);
+ /* Before ldiapp-0. */
+ __asm__ volatile ("ldiapp x19, x20, [x21]\n" : : : "x19", "x20", "memory");
+ /* After ldiapp-0. */
+
+ PREPARE_GPR (0);
+ /* Before ldiapp-1. */
+ __asm__ volatile ("ldiapp w19, w20, [x21]\n" : : : "x19", "x20", "memory");
+ /* After ldiapp-1. */
+
+ PREPARE_GPR (0);
+ /* Before ldiapp-2. */
+ __asm__ volatile ("ldiapp x19, x20, [x21], #16\n"
+ :
+ :
+ : "x19", "x20", "x21", "memory");
+ /* After ldiapp-2. */
+
+ PREPARE_GPR (0);
+ /* Before ldiapp-3. */
+ __asm__ volatile ("ldiapp w19, w20, [x21], #8\n"
+ :
+ :
+ : "x19", "x20", "x21", "memory");
+ /* After ldiapp-3. */
+ /* Register overlap between source and destination registers. Since there is
+ no offset, writeback is disabled. */
+
+ PREPARE_GPR (0);
+ /* Before ldiapp-4. */
+ __asm__ volatile ("ldiapp x21, x20, [x21]\n" : : : "x20", "x21", "memory");
+ /* After ldiapp-4. */
+
+ PREPARE_GPR (0);
+ /* Before ldiapp-5. */
+ __asm__ volatile ("ldiapp w21, w20, [x21]\n" : : : "x20", "x21", "memory");
+ /* After ldiapp-5. */
+
+ PREPARE_GPR (0);
+ /* Before stilp-0. */
+ __asm__ volatile ("stilp x19, x20, [x21]\n" : : : "memory");
+ /* After stilp-0. */
+
+ PREPARE_GPR (0);
+ /* Before stilp-1. */
+ __asm__ volatile ("stilp w19, w20, [x21]\n" : : : "memory");
+ /* After stilp-1. */
+
+ PREPARE_GPR (16);
+ /* Before stilp-2. */
+ __asm__ volatile ("stilp x19, x20, [x21, #-16]!\n" : : : "x21", "memory");
+ /* After stilp-2. */
+
+ PREPARE_GPR (8);
+ /* Before stilp-3. */
+ __asm__ volatile ("stilp w19, w20, [x21, #-8]!\n" : : : "x21", "memory");
+ /* After stilp-3. */
+ /* Register overlap. Since there is no offset, writeback is disabled. */
+
+ PREPARE_GPR (0);
+ /* Before stilp-4. */
+ __asm__ volatile ("stilp x21, x20, [x21]\n" : : : "memory");
+ /* After stilp-4. */
+
+ PREPARE_GPR (0);
+ /* Before stilp-5. */
+ __asm__ volatile ("stilp w21, w20, [x21]\n" : : : "memory");
+ /* After stilp-5. */
+
+ PREPARE_GPR (0);
+ /* Before ldapr-0. */
+ __asm__ volatile ("ldapr x19, [x21], #8\n" : : : "x19", "x21", "memory");
+ /* After ldapr-0. */
+
+ PREPARE_GPR (0);
+ /* Before ldapr-1. */
+ __asm__ volatile ("ldapr w19, [x21], #4\n" : : : "x19", "x21", "memory");
+ /* After ldapr-1. */
+
+ PREPARE_GPR (8);
+ /* Before stlr-0. */
+ __asm__ volatile ("stlr x19, [x21, #-8]!\n" : : : "x21", "memory");
+ /* After stlr-0. */
+
+ PREPARE_GPR (4);
+ /* Before stlr-1. */
+ __asm__ volatile ("stlr w19, [x21, #-4]!\n" : : : "x21", "memory");
+ /* After stlr-1. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before ldap1-0. */
+ __asm__ volatile ("ldap1 {v22.d}[0], [x21]\n" : : : "v22", "memory");
+ /* After ldap1-0. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before stl1-0. */
+ __asm__ volatile ("stl1 {v22.d}[0], [x21]\n" : : : "memory");
+ /* After stl1-0. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before ldapur-0. */
+ __asm__ volatile ("ldapur d22, [x21]\n" : : : "v22", "memory");
+ /* After ldapur-0. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before stlur-0. */
+ __asm__ volatile ("stlur d22, [x21]\n" : : : "memory");
+ /* After stlur-0. */
+
+ PREPARE_VECTOR_REG (256);
+ /* Before ldapur-1. */
+ __asm__ volatile ("ldapur d22, [x21, #-256]\n" : : : "v22", "memory");
+ /* After ldapur-1. */
+
+ PREPARE_VECTOR_REG (256);
+ /* Before stlur-1. */
+ __asm__ volatile ("stlur d22, [x21, #-256]\n" : : : "memory");
+ /* After stlur-1. */
+
+ PREPARE_VECTOR_REG (-255);
+ /* Before ldapur-2. */
+ __asm__ volatile ("ldapur d22, [x21, #255]\n" : : : "v22", "memory");
+ /* After ldapur-2. */
+
+ PREPARE_VECTOR_REG (-255);
+ /* Before stlur-2. */
+ __asm__ volatile ("stlur d22, [x21, #255]\n" : : : "memory");
+ /* After stlur-2. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before ldapur-3. */
+ __asm__ volatile ("ldapur h22, [x21]\n" : : : "v22", "memory");
+ /* After ldapur-3. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before stlur-3. */
+ __asm__ volatile ("stlur h22, [x21]\n" : : : "memory");
+ /* After stlur-3. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before ldapur-4. */
+ __asm__ volatile ("ldapur s22, [x21]\n" : : : "v22", "memory");
+ /* After ldapur-4. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before stlur-4. */
+ __asm__ volatile ("stlur s22, [x21]\n" : : : "memory");
+ /* After stlur-4. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before ldapur-5. */
+ __asm__ volatile ("ldapur d22, [x21]\n" : : : "v22", "memory");
+ /* After ldapur-5. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before stlur-5. */
+ __asm__ volatile ("stlur d22, [x21]\n" : : : "memory");
+ /* After stlur-5. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before ldapur-6. */
+ __asm__ volatile ("ldapur q22, [x21]\n" : : : "v22", "memory");
+ /* After ldapur-6. */
+
+ PREPARE_VECTOR_REG (0);
+ /* Before stlur-6. */
+ __asm__ volatile ("stlur q22, [x21]\n" : : : "memory");
+ /* After stlur-6. */
+
+ return 0;
+}
diff --git a/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.exp b/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.exp
new file mode 100644
index 00000000..b9e48147
--- /dev/null
+++ b/gdb/testsuite/gdb.reverse/aarch64-lrcpc3.exp
@@ -0,0 +1,190 @@
+# Copyright 2024-2026 Free Software Foundation, Inc.
+
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see .
+
+# Test instruction record for AArch64 FEAT_LRCPC3 instructions.
+# Based on gdb.reverse/aarch64-mops.exp
+#
+# The basic flow of the record tests are:
+# 1) Stop before executing the instructions of interest. Record
+# the initial value of the registers that the instruction will
+# change, i.e. the destination register.
+# 2) Execute the instructions. Record the new value of the
+# registers that changed.
+# 3) Reverse the direction of the execution and execute back to
+# just before the instructions of interest. Record the final
+# value of the registers of interest.
+# 4) Check that the initial and new values of the registers are
+# different, i.e. the instruction changed the registers as expected.
+# 5) Check that the initial and final values of the registers are
+# the same, i.e. GDB record restored the registers to their
+# original values.
+
+require allow_aarch64_lrcpc3_tests
+
+standard_testfile
+
+if {[prepare_for_testing "failed to prepare" ${testfile} ${srcfile} \
+ [list debug additional_flags=-march=armv8-a+rcpc3]]} {
+ return
+}
+
+if {![runto_main]} {
+ return
+}
+
+gdb_test_no_output "record full"
+
+proc test_single_asm {name diff_reg diff_mem same_reg same_mem} {
+ with_test_prefix $name {
+
+ set before_seq [gdb_get_line_number "Before ${name}"]
+ set after_seq [gdb_get_line_number "After ${name}"]
+
+ set insn [lindex [split $name "-"] 0]
+
+ gdb_test "break $before_seq" \
+ "Breakpoint ${::decimal} at ${::hex}: file .*/aarch64-lrcpc3.c, line ${::decimal}\\." \
+ "$insn before instruction sequence"
+
+ gdb_continue_to_breakpoint "about to execute instruction sequence" \
+ [multi_line ".*/aarch64-lrcpc3.c:${::decimal}" \
+ "${::decimal}\[ \t\]+__asm__ volatile \\(\"${insn} .*\".*"]
+
+ # Depending on the compiler, the line number information may put GDB a few
+ # instructions before the beginning of the asm statement.
+ arrive_at_instruction $insn
+ # Add a breakpoint that we're sure is at the prologue instruction.
+ gdb_test "break *\$pc" \
+ "Breakpoint ${::decimal} at ${::hex}: file .*/aarch64-lrcpc3.c, line ${::decimal}\\." \
+ "break at prologue instruction"
+
+ # Record the initial memory and register values.
+ set regs [concat $diff_reg $same_reg]
+ set mem [concat $diff_mem $same_mem]
+ foreach r $regs {
+ set ${r}_initial [capture_command_output "info register $r" ""]
+ }
+ foreach m $mem {
+ set ${m}_initial [capture_command_output "x/x $m" ""]
+ }
+
+ gdb_test "break $after_seq" \
+ "Breakpoint ${::decimal} at ${::hex}: file .*/aarch64-lrcpc3.c, line ${::decimal}\\." \
+ "$insn after instruction sequence"
+ gdb_continue_to_breakpoint "executed instruction sequence" \
+ [multi_line ".*/aarch64-lrcpc3.c:${::decimal}" ".*"]
+
+ # Record the new memory and register values.
+ foreach r $regs {
+ set ${r}_new [capture_command_output "info register $r" ""]
+ }
+ foreach m $mem {
+ set ${m}_new [capture_command_output "x/x $m" ""]
+ }
+
+ # Execute in reverse to before the instruction sequence.
+ gdb_test_no_output "set exec-direction reverse"
+
+ gdb_continue_to_breakpoint "reversed execution of instruction sequence" \
+ [multi_line ".*/aarch64-lrcpc3.c:${::decimal}" \
+ "${::decimal}\[ \t\]+__asm__ volatile \\(\"${insn} .*\".*"]
+
+ # Record the final memory and register values.
+ foreach r $regs {
+ set ${r}_final [capture_command_output "info register $r" ""]
+ }
+ foreach m $mem {
+ set ${m}_final [capture_command_output "x/x $m" ""]
+ }
+
+ foreach v [concat $same_reg $same_mem] {
+ gdb_assert ![string compare [set ${v}_initial] [set ${v}_new]] \
+ "check $v initial value versus $v new value"
+ gdb_assert ![string compare [set ${v}_initial] [set ${v}_final]] \
+ "check $v initial value versus $v final value"
+ }
+
+ foreach v [concat $diff_reg $diff_mem] {
+ gdb_assert [string compare [set ${v}_initial] [set ${v}_new]] \
+ "check $v initial value versus $v new value"
+ gdb_assert ![string compare [set ${v}_initial] [set ${v}_final]] \
+ "check $v initial value versus $v final value"
+ }
+
+ # Restore forward execution and go to end of recording.
+ gdb_test_no_output "set exec-direction forward"
+ gdb_test "record goto end" \
+ [multi_line \
+ "Go forward to insn number ${::decimal}" \
+ "#0 main \\(\\) at .*/aarch64-lrcpc3.c:${::decimal}" \
+ ".*"]
+ }
+}
+
+set ldiapp_cases {
+ { ldiapp-0 { x19 x20 } { } { x21 } { src } }
+ { ldiapp-1 { w19 w20 } { } { x21 } { src } }
+ { ldiapp-2 { x19 x20 x21 } { } { } { src } }
+ { ldiapp-3 { w19 w20 x21 } { } { } { src } }
+ { ldiapp-4 { x21 x20 } { } { } { src } }
+ { ldiapp-5 { w21 w20 } { } { } { src } }
+}
+
+set stilp_cases {
+ { stilp-0 { } { src } { x19 x20 x21 } { } }
+ { stilp-1 { } { src } { w19 w20 x21 } { } }
+ { stilp-2 { x21 } { src } { x19 x20 } { } }
+ { stilp-3 { x21 } { src } { x19 x20 } { } }
+ { stilp-4 { } { src } { x20 x21 } { } }
+ { stilp-5 { } { src } { w20 x21 } { } }
+}
+
+set ldapr_stlr_cases {
+ { ldapr-0 { x19 x21 } { } { } { src } }
+ { ldapr-1 { w19 x21 } { } { } { src } }
+ { stlr-0 { x21 } { src } { x19 } { } }
+ { stlr-1 { x21 } { src } { w19 } { } }
+}
+
+set ldap1_stl1_cases {
+ { ldap1-0 { v22 } { } { x21 } { src } }
+ { stl1-0 { } { src } { v22 } { } }
+}
+
+set ldapur_stlur_cases {
+ { ldapur-0 { v22 } { } { x21 } { src } }
+ { stlur-0 { } { src } { x21 v22 } { } }
+ { ldapur-1 { v22 } { } { x21 } { src } }
+ { stlur-1 { } { src } { x21 v22 } { } }
+ { ldapur-2 { v22 } { } { x21 } { src } }
+ { stlur-2 { } { src } { x21 v22 } { } }
+ { ldapur-3 { v22 } { } { x21 } { src } }
+ { stlur-3 { } { src } { x21 v22 } { } }
+ { ldapur-4 { v22 } { } { x21 } { src } }
+ { stlur-4 { } { src } { x21 v22 } { } }
+ { ldapur-5 { v22 } { } { x21 } { src } }
+ { stlur-5 { } { src } { x21 v22 } { } }
+ { ldapur-6 { v22 } { } { x21 } { src } }
+ { stlur-6 { } { src } { x21 v22 } { } }
+}
+
+set all_cases [concat \
+ $ldiapp_cases $stilp_cases $ldapr_stlr_cases \
+ $ldap1_stl1_cases $ldapur_stlur_cases]
+
+foreach c $all_cases {
+ lassign $c name diff_reg diff_mem same_reg same_mem
+ test_single_asm $name $diff_reg $diff_mem $same_reg $same_mem
+}
diff --git a/gdb/testsuite/lib/gdb.exp b/gdb/testsuite/lib/gdb.exp
index cd59ada7..07f9c8df 100644
--- a/gdb/testsuite/lib/gdb.exp
+++ b/gdb/testsuite/lib/gdb.exp
@@ -5287,6 +5287,65 @@ gdb_caching_proc allow_aarch64_fpmr_tests {} {
return $allow_fpmr_tests
}
+# Run a test on the target to see if it supports AArch64 LRCPC3 (Load-Acquire
+# RCpc instructions) extensions. Return 1 if so, 0 if it does not. Note this
+# causes a restart of GDB.
+
+gdb_caching_proc allow_aarch64_lrcpc3_tests {} {
+ global srcdir subdir gdb_prompt inferior_exited_re
+
+ set me "allow_aarch64_lrcpc3_tests"
+
+ if { ![is_aarch64_target] } {
+ return 0
+ }
+
+ # Take the opportunity to check whether the toolchain knows about LRCPC3.
+ set compile_flags "{additional_flags=-march=armv8-a+rcpc3}"
+
+ # Compile a program that tests the LRCPC3 feature.
+ set src {
+ #include
+ #include
+
+ /* Feature check for LRCPC3. */
+ #ifndef HWCAP2_LRCPC3
+ #define HWCAP2_LRCPC3 (1ULL << 46)
+ #endif
+
+ int main (void) {
+ bool lrcpc3_supported = getauxval (AT_HWCAP2) & HWCAP2_LRCPC3;
+
+ /* Return success if LRCPC3 is supported. */
+ return !lrcpc3_supported;
+ }
+ }
+
+ if {![gdb_simple_compile $me $src executable $compile_flags]} {
+ return 0
+ }
+
+ # Compilation succeeded so now run it via gdb.
+ clean_restart
+ gdb_load $obj
+ gdb_run_cmd
+ gdb_expect {
+ -re ".*$inferior_exited_re normally.*${gdb_prompt} $" {
+ verbose -log "\n$me: lrcpc3 support detected"
+ set allow_lrcpc3_tests 1
+ }
+ -re ".*$inferior_exited_re with code 01.*${gdb_prompt} $" {
+ verbose -log "\n$me: lrcpc3 support not detected"
+ set allow_lrcpc3_tests 0
+ }
+ }
+ gdb_exit
+ remote_file build delete $obj
+
+ verbose "$me: returning $allow_lrcpc3_tests" 2
+ return $allow_lrcpc3_tests
+}
+
# Run a test on the target to see if it supports the AArch64 CSSC feature.
# Return 1 if so, 0 if it does not. Note this causes a restart of GDB.