diff options
| author | Maxime Chevalier-Boisvert <maxime.chevalierboisvert@shopify.com> | 2020-12-14 13:26:33 -0500 |
|---|---|---|
| committer | Alan Wu <XrXr@users.noreply.github.com> | 2021-10-20 18:19:26 -0400 |
| commit | 868a6809e7d15b95f14bff822268e2962747fb06 (patch) | |
| tree | e66e2b51d3e3fe105c1d07e9235a94c9788a2645 | |
| parent | 8ae354e9bedbe5995e97206b170f3e406fc5b617 (diff) | |
Add sign-extended mode for test() instruction
| -rw-r--r-- | ujit_asm.c | 34 | ||||
| -rw-r--r-- | ujit_asm_tests.c | 1 |
2 files changed, 24 insertions, 11 deletions
diff --git a/ujit_asm.c b/ujit_asm.c index 4cb7bb7caa..4fb0cc764a 100644 --- a/ujit_asm.c +++ b/ujit_asm.c @@ -1516,22 +1516,34 @@ void test(codeblock_t* cb, x86opnd_t rm_opnd, x86opnd_t test_opnd) if (test_opnd.type == OPND_IMM) { x86opnd_t imm_opnd = test_opnd; - assert (imm_opnd.as.imm >= 0); - assert (unsig_imm_size(imm_opnd.as.unsig_imm) <= 32); - assert (unsig_imm_size(imm_opnd.as.unsig_imm) <= rm_opnd.num_bits); - // Use the smallest operand size possible - rm_opnd = resize_opnd(rm_opnd, unsig_imm_size(imm_opnd.as.unsig_imm)); - - if (rm_opnd.num_bits == 8) + if (imm_opnd.as.imm >= 0) { - cb_write_rm(cb, false, false, NO_OPND, rm_opnd, 0x00, 1, 0xF6); - cb_write_int(cb, imm_opnd.as.imm, rm_opnd.num_bits); + assert (unsig_imm_size(imm_opnd.as.unsig_imm) <= 32); + assert (unsig_imm_size(imm_opnd.as.unsig_imm) <= rm_opnd.num_bits); + + // Use the smallest operand size possible + rm_opnd = resize_opnd(rm_opnd, unsig_imm_size(imm_opnd.as.unsig_imm)); + + if (rm_opnd.num_bits == 8) + { + cb_write_rm(cb, false, false, NO_OPND, rm_opnd, 0x00, 1, 0xF6); + cb_write_int(cb, imm_opnd.as.imm, rm_opnd.num_bits); + } + else + { + cb_write_rm(cb, rm_opnd.num_bits == 16, false, NO_OPND, rm_opnd, 0x00, 1, 0xF7); + cb_write_int(cb, imm_opnd.as.imm, rm_opnd.num_bits); + } } else { - cb_write_rm(cb, rm_opnd.num_bits == 16, false, NO_OPND, rm_opnd, 0x00, 1, 0xF7); - cb_write_int(cb, imm_opnd.as.imm, rm_opnd.num_bits); + // This mode only applies to 64-bit R/M operands with 32-bit signed immediates + assert (imm_opnd.as.imm < 0); + assert (sig_imm_size(imm_opnd.as.imm) <= 32); + assert (rm_opnd.num_bits == 64); + cb_write_rm(cb, false, true, NO_OPND, rm_opnd, 0x00, 1, 0xF7); + cb_write_int(cb, imm_opnd.as.imm, 32); } } else diff --git a/ujit_asm_tests.c b/ujit_asm_tests.c index 532fb5367c..8f2fbdfcbf 100644 --- a/ujit_asm_tests.c +++ b/ujit_asm_tests.c @@ -315,6 +315,7 @@ void run_tests() cb_set_pos(cb, 0); test(cb, mem_opnd(8, RSI, 16), imm_opnd(1)); check_bytes(cb, "F6461001"); cb_set_pos(cb, 0); test(cb, mem_opnd(8, RSI, -16), imm_opnd(1)); check_bytes(cb, "F646F001"); cb_set_pos(cb, 0); test(cb, mem_opnd(32, RSI, 64), EAX); check_bytes(cb, "854640"); + cb_set_pos(cb, 0); test(cb, mem_opnd(64, RSI, 64), imm_opnd(~0x08)); check_bytes(cb, "48F74640F7FFFFFF"); // xor cb_set_pos(cb, 0); xor(cb, EAX, EAX); check_bytes(cb, "31C0"); |