@@ -130,6 +130,7 @@ extern bool loongarch_symbol_binds_local_p (const_rtx);
extern const char *current_section_name (void);
extern unsigned int current_section_flags (void);
extern bool loongarch_use_ins_ext_p (rtx, HOST_WIDE_INT, HOST_WIDE_INT);
+extern bool loongarch_check_zero_div_p (void);
union loongarch_gen_fn_ptrs
{
@@ -2104,7 +2104,7 @@ loongarch_load_store_insns (rtx mem, rtx_insn *insn)
/* Return true if we need to trap on division by zero. */
-static bool
+bool
loongarch_check_zero_div_p (void)
{
/* if -m[no-]check-zero-division is given explicitly. */
@@ -110,6 +110,8 @@ (define_constants
;;
;; ....................
+(define_attr "enabled" "no,yes" (const_string "yes"))
+
(define_attr "got" "unset,load"
(const_string "unset"))
@@ -763,26 +765,36 @@ (define_expand "<optab><mode>3"
})
(define_insn "*<optab><mode>3"
- [(set (match_operand:GPR 0 "register_operand" "=&r")
- (any_div:GPR (match_operand:GPR 1 "register_operand" "r")
- (match_operand:GPR 2 "register_operand" "r")))]
+ [(set (match_operand:GPR 0 "register_operand" "=r,&r,&r")
+ (any_div:GPR (match_operand:GPR 1 "register_operand" "r,r,0")
+ (match_operand:GPR 2 "register_operand" "r,r,r")))]
""
{
return loongarch_output_division ("<insn>.<d><u>\t%0,%1,%2", operands);
}
[(set_attr "type" "idiv")
- (set_attr "mode" "<MODE>")])
+ (set_attr "mode" "<MODE>")
+ (set (attr "enabled")
+ (if_then_else
+ (match_test "!!which_alternative == loongarch_check_zero_div_p()")
+ (const_string "yes")
+ (const_string "no")))])
(define_insn "<optab>di3_fake"
- [(set (match_operand:SI 0 "register_operand" "=&r")
- (any_div:SI (match_operand:DI 1 "register_operand" "r")
- (match_operand:DI 2 "register_operand" "r")))]
+ [(set (match_operand:SI 0 "register_operand" "=r,&r,&r")
+ (any_div:SI (match_operand:DI 1 "register_operand" "r,r,0")
+ (match_operand:DI 2 "register_operand" "r,r,r")))]
""
{
return loongarch_output_division ("<insn>.w<u>\t%0,%1,%2", operands);
}
[(set_attr "type" "idiv")
- (set_attr "mode" "SI")])
+ (set_attr "mode" "SI")
+ (set (attr "enabled")
+ (if_then_else
+ (match_test "!!which_alternative == loongarch_check_zero_div_p()")
+ (const_string "yes")
+ (const_string "no")))])
;; Floating point multiply accumulate instructions.
new file mode 100644
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcheck-zero-division" } */
+/* { dg-final { scan-assembler "div.\[wd\]\t\\\$r4,\\\$r4,\\\$r5" } } */
+
+long
+div(long a, long b)
+{
+ return a / b;
+}
new file mode 100644
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mno-check-zero-division" } */
+/* { dg-final { scan-assembler "div.\[wd\]\t\\\$r4,\\\$r5,\\\$r4" } } */
+
+long
+div(long a, long b)
+{
+ return b / a;
+}
new file mode 100644
@@ -0,0 +1,9 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mcheck-zero-division" } */
+/* { dg-final { scan-assembler-not "div.\[wd\]\t\\\$r4,\\\$r5,\\\$r4" } } */
+
+long
+div(long a, long b)
+{
+ return b / a;
+}
Currently in the description of LoongArch integer division instructions, the output is marked as earlyclobbered ('&'). It's necessary when loongarch_check_zero_div_p() because clobbering operand 2 (divisor) will make the checking for zero divisor impossible. But, for -mno-check-zero-division (the default of GCC >= 12.2 for optimized code), the output is not earlyclobbered at all. And, the read of operand 1 only occurs before clobbering the output. So we make three alternatives for an idiv instruction: * (=r,r,r): For -mno-check-zero-division. * (=&r,r,r): For -mcheck-zero-division. * (=&r,0,r): For -mcheck-zero-division, to explicitly allow patterns like "div.d $a0, $a0, $a1". gcc/ChangeLog: * config/loongarch/loongarch.cc (loongarch_check_zero_div_p): Remove static, for use in the machine description file. * config/loongarch/loongarch-protos.h: (loongarch_check_zero_div_p): Add prototype. * config/loongarch/loongarch.md (enabled): New attr. (*<optab><mode>3): Add (=r,r,r) and (=&r,0,r) alternatives for idiv. Conditionally enable the alternatives using loongarch_check_zero_div_p. (<optab>di3_fake): Likewise. gcc/testsuite/ChangeLog: * gcc.target/loongarch/div-1.c: New test. * gcc.target/loongarch/div-2.c: New test. * gcc.target/loongarch/div-3.c: New test. --- gcc/config/loongarch/loongarch-protos.h | 1 + gcc/config/loongarch/loongarch.cc | 2 +- gcc/config/loongarch/loongarch.md | 28 +++++++++++++++------- gcc/testsuite/gcc.target/loongarch/div-1.c | 9 +++++++ gcc/testsuite/gcc.target/loongarch/div-2.c | 9 +++++++ gcc/testsuite/gcc.target/loongarch/div-3.c | 9 +++++++ 6 files changed, 49 insertions(+), 9 deletions(-) create mode 100644 gcc/testsuite/gcc.target/loongarch/div-1.c create mode 100644 gcc/testsuite/gcc.target/loongarch/div-2.c create mode 100644 gcc/testsuite/gcc.target/loongarch/div-3.c