From: Guinevere Larsen Date: Wed, 3 Jun 2026 11:58:10 +0000 (-0300) Subject: gdb/record: Add support for recording BMI1 instructions X-Git-Url: http://git.ipfire.org/gitweb.cgi?a=commitdiff_plain;h=873816999f792e48eee4f1d6cd21faecb9f419fe;p=thirdparty%2Fbinutils-gdb.git gdb/record: Add support for recording BMI1 instructions This commit adds support for recording all instructions of the Bit Manipulation Instruction set 1, for x86 cpus. The specific instructions are: * andn * bls[i|r|msk] * bextr * [l|t]zcnt Also add them to the avx test. While BMI is a different set of instructions, there are no currently existing CPUs that have access to AVX2 and don't have access to BMI1 and BMI2, so it seems like a reasonable idea to keep them together, as the avx test already requires AVX2. Approved-By: Guinevere Larsen --- diff --git a/gdb/i386-tdep.c b/gdb/i386-tdep.c index a09eac00251..bf131aaf96a 100644 --- a/gdb/i386-tdep.c +++ b/gdb/i386-tdep.c @@ -5125,25 +5125,52 @@ i386_record_vex (struct i386_record_s *ir, uint8_t vex_w, uint8_t vex_r, case 0xe5: /* VPMULHW */ case 0xe6: /* VCVTDQ2PD, VCVTTPD2DQ and VCVTPD2DQ. */ case 0xf1: /* VPSLLW, dynamic shift. */ - case 0xf2: /* VPSLLD, dynamic shift. */ - case 0xf3: /* VPSLLQ, dynamic shift. */ + case 0xf2: /* VPSLLD, dynamic shift and ANDN. */ + case 0xf3: /* VPSLLQ, dynamic shift and BLSI, BLSR and BLSMSK. */ case 0xf4: /* VPMULUDQ */ case 0xf6: /* VPSADBW. */ case 0xfc: /* VPADDB */ case 0xfd: /* VPADDW */ case 0xfe: /* VPADDD */ { - /* This set of instructions all share the same exact way to encode - the destination register, so there's no reason to try and - differentiate them. */ i386_record_modrm (ir); int reg_offset = ir->reg + vex_r * 8; - gdb_assert (tdep->num_ymm_regs > reg_offset); - record_full_arch_list_add_reg (ir->regcache, - tdep->ymm0_regnum + reg_offset); + if (opcode == 0xf2 && ir->map_select == 2) /* ANDN. */ + { + record_full_arch_list_add_reg (ir->regcache, + ir->regmap[X86_RECORD_REAX_REGNUM + + reg_offset]); + record_full_arch_list_add_reg + (ir->regcache, ir->regmap[X86_RECORD_EFLAGS_REGNUM]); + } + else if (opcode == 0xf3 && ir->map_select == 2) + { + /* BLSI, BLSR and BLSMSK. */ + record_full_arch_list_add_reg (ir->regcache, + ir->regmap[X86_RECORD_REAX_REGNUM + + ir->vvvv]); + record_full_arch_list_add_reg + (ir->regcache, ir->regmap[X86_RECORD_EFLAGS_REGNUM]); + } + else + { + /* This set of instructions all share the same exact way to + encode the destination register, so there's no reason to + try and differentiate them. */ + gdb_assert (tdep->num_ymm_regs > reg_offset); + record_full_arch_list_add_reg (ir->regcache, + tdep->ymm0_regnum + reg_offset); + } } break; + case 0xf7: /* BEXTR. */ + i386_record_modrm (ir); + record_full_arch_list_add_reg (ir->regcache, + ir->regmap[X86_RECORD_REAX_REGNUM + + ir->reg + vex_r * 8]); + break; + case 0x2e: /* VUCOMIS[S|D]. */ case 0x2f: /* VCOMIS[S|D]. */ { @@ -7029,8 +7056,9 @@ Do you want to stop the program?"), I386_RECORD_FULL_ARCH_LIST_ADD_REG (X86_RECORD_EFLAGS_REGNUM); break; - case 0x0fbc: /* bsf */ - case 0x0fbd: /* bsr */ + case 0x0fbc: /* bsf and tzcnt. */ + case 0x0fbd: /* bsr and lzcnt. */ + i386_record_modrm (&ir); I386_RECORD_FULL_ARCH_LIST_ADD_REG (ir.reg | rex_r); I386_RECORD_FULL_ARCH_LIST_ADD_REG (X86_RECORD_EFLAGS_REGNUM); break; diff --git a/gdb/testsuite/gdb.reverse/i386-avx-reverse.c b/gdb/testsuite/gdb.reverse/i386-avx-reverse.c index cfbd77c8992..190bc6f4a7a 100644 --- a/gdb/testsuite/gdb.reverse/i386-avx-reverse.c +++ b/gdb/testsuite/gdb.reverse/i386-avx-reverse.c @@ -765,6 +765,43 @@ convert_test () return 0; /* end convert_test */ } +int +bmi_test () +{ + /* start bmi_test. */ + /* Using GDB, load these values onto registers for testing. + eax = 0x1312 + ebx = 0xdeadbeef + ecx = 0xcafeface + r8 = 0 + this way it's easy to confirm we're undoing things correctly. */ + + asm volatile ("andn %rbx, %rax, %r8"); + asm volatile ("andn %ebx, %eax, %ecx"); + + asm volatile ("bextr %rcx, %r8, %rbx"); + asm volatile ("bextr %ebx, %ecx, %r8d"); + + asm volatile ("blsi %rax, %rcx"); + asm volatile ("blsi %ebx, %r8d"); + + asm volatile ("blsmsk %r8, %rbx"); + asm volatile ("blsmsk %eax, %eax"); + + asm volatile ("blsr %rcx, %rbx"); + asm volatile ("blsr %r8d, %ecx"); + + asm volatile ("lzcnt %rax, %r8"); + asm volatile ("lzcnt %eax, %ecx"); + asm volatile ("lzcnt %ax, %bx"); + + asm volatile ("tzcnt %rax, %rcx"); + asm volatile ("tzcnt %eax, %ebx"); + asm volatile ("tzcnt %ax, %r8w"); + + return 0; /* end bmi_test */ +} + /* This include is used to allocate the dynamic buffer and have the pointers aligned to a 32-bit boundary, so we can test instructions that require aligned memory. */ @@ -806,5 +843,6 @@ main () compare_test (); pack_test (); convert_test (); + bmi_test (); return 0; /* end of main */ } diff --git a/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp b/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp index 9aef8f111da..811b085f4a6 100644 --- a/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp +++ b/gdb/testsuite/gdb.reverse/i386-avx-reverse.exp @@ -23,6 +23,8 @@ require supports_reverse require have_avx require have_avx2 +# This test also requires BMI1 support. All real hardware in existence +# that supports AVX2 also supports those though, so we don't check it. # TODO: this is the case because I used xmm15 all over the test. # Some parts of the test require xmm15 to validate some code paths, but @@ -1195,3 +1197,42 @@ if {[record_full_function "convert"] == true} { } gdb_test "finish" "Run till exit from.*convert_test.*" \ "leaving convert" + + +# Preparation and testing BMI instructions. +gdb_test_no_output \ + "set \$r8 = 0" "set r8 for bmi test" +gdb_test_no_output \ + "set \$eax = 0x1312" "set eax for bmi test" +gdb_test_no_output "set \$ebx = 0xdeadbeef" "set ebx for bmi test" +gdb_test_no_output "set \$ecx = 0xcafeface" "set ecx for bmi test" + +if {[record_full_function "bmi"] == true} { + + test_one_general_register "tzcnt" "r8" "0x3e" + test_one_general_register "tzcnt" "ebx" "0xe" + test_one_general_register "tzcnt" "ecx" "0x1e" + + test_one_general_register "lzcnt" "ebx" "0x0" + test_one_general_register "lzcnt" "ecx" "0x0" + test_one_general_register "lzcnt" "r8" "0x0" + + test_one_general_register "blsr" "ecx" "0x2" + test_one_general_register "blsr" "ebx" "0xffffffff" + + test_one_general_register "blsmsk" "eax" "0x1312" + test_one_general_register "blsmsk" "ebx" "0x0" + + test_one_general_register "blsi" "r8" "0x0" + test_one_general_register "blsi" "ecx" "0xdeadaced" + + test_one_general_register "bextr" "eax" "0x1312" + test_one_general_register "bextr" "ebx" "0xdeadbeef" + + test_one_general_register "andn" "ecx" "0xcafeface" + test_one_general_register "andn" "r8" "0x0" +} else { + untested "couldn't run bmi tests" +} +gdb_test "finish" "Run till exit from.*bmi_test.*" \ + "leaving bmi"