target/i386: Fix BEXTR instruction

There were two problems here: not limiting the input to operand bits,
and not correctly handling large extraction length.

Resolves: https://gitlab.com/qemu-project/qemu/-/issues/1372
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>
Message-Id: <20230114230542.3116013-3-richard.henderson@linaro.org>
Cc: qemu-stable@nongnu.org
Fixes: 1d0b926150e5 ("target/i386: move scalar 0F 38 and 0F 3A instruction to new decoder", 2022-10-18)
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

1 files changed, 12 insertions, 0 deletions

diff --git a/tests/tcg/i386/test-i386-bmi2.c b/tests/tcg/i386/test-i386-bmi2.c
index 3c3ef85513..982d4abda4 100644
--- a/tests/tcg/i386/test-i386-bmi2.c
+++ b/tests/tcg/i386/test-i386-bmi2.c
@@ -99,6 +99,9 @@ int main(int argc, char *argv[]) {
     result = bextrq(mask, 0x10f8);
     assert(result == 0);
 
+    result = bextrq(0xfedcba9876543210ull, 0x7f00);
+    assert(result == 0xfedcba9876543210ull);
+
     result = blsiq(0x30);
     assert(result == 0x10);
 
@@ -164,6 +167,15 @@ int main(int argc, char *argv[]) {
     result = bextrl(mask, 0x1038);
     assert(result == 0);
 
+    result = bextrl((reg_t)0x8f635a775ad3b9b4ull, 0x3018);
+    assert(result == 0x5a);
+
+    result = bextrl((reg_t)0xfedcba9876543210ull, 0x7f00);
+    assert(result == 0x76543210u);
+
+    result = bextrl(-1, 0);
+    assert(result == 0);
+
     result = blsil(0xffff);
     assert(result == 1);