This patch adds a new pattern, *thumb2_csneg, for generating CSNEG instructions. It also restricts *if_neg_move and *thumb2_negscc to only match if !TARGET_COND_ARITH which prevents undesirable matches during ifcvt.
Regression tested on arm-none-eabi.
2020-07-30: Sudakshina Das <sudi....@arm.com>
Omar Tahir <omar.ta...@arm.com>
* config/arm/thumb2.md (*thumb2_csneg): New.
(*thumb2_negscc): Don't match if TARGET_COND_ARITH.
* config/arm/arm.md (*if_neg_move): Don't match if
TARGET_COND_ARITH.
gcc/testsuite/ChangeLog:
2020-07-30: Sudakshina Das <sudi....@arm.com>
Omar Tahir <omar.ta...@arm.com>
* gcc.target/arm/csneg.c: New test.
diff --git a/gcc/config/arm/arm.md b/gcc/config/arm/arm.md
index a6a31f8f4ef..950e46edfee 100644
--- a/gcc/config/arm/arm.md
+++ b/gcc/config/arm/arm.md
@@ -11211,7 +11211,7 @@
[(match_operand 3 "cc_register" "") (const_int 0)])
(neg:SI (match_operand:SI 2 "s_register_operand" "l,r"))
(match_operand:SI 1 "s_register_operand" "0,0")))]
- "TARGET_32BIT"
+ "TARGET_32BIT && !TARGET_COND_ARITH"
"#"
"&& reload_completed"
[(cond_exec (match_op_dup 4 [(match_dup 3) (const_int 0)])
diff --git a/gcc/config/arm/thumb2.md b/gcc/config/arm/thumb2.md
index 79cf684e5cb..d12467d7644 100644
--- a/gcc/config/arm/thumb2.md
+++ b/gcc/config/arm/thumb2.md
@@ -880,7 +880,7 @@
[(match_operand:SI 1 "s_register_operand" "r")
(match_operand:SI 2 "arm_rhs_operand" "rI")])))
(clobber (reg:CC CC_REGNUM))]
- "TARGET_THUMB2"
+ "TARGET_THUMB2 && !TARGET_COND_ARITH"
"#"
"&& reload_completed"
[(const_int 0)]
@@ -970,6 +970,20 @@
(set_attr "predicable" "no")]
)
+(define_insn "*thumb2_csneg"
+ [(set (match_operand:SI 0 "arm_general_register_operand" "=r, r")
+ (if_then_else:SI
+ (match_operand 1 "arm_comparison_operation" "")
+ (neg:SI (match_operand:SI 2 "arm_general_register_operand" "r, r"))
+ (match_operand:SI 3 "reg_or_zero_operand" "r, Z")))]
+ "TARGET_COND_ARITH"
+ "@
+ csneg\\t%0, %3, %2, %D1
+ csneg\\t%0, zr, %2, %D1"
+ [(set_attr "type" "csel")
+ (set_attr "predicable" "no")]
+)
+
(define_insn "*thumb2_movcond"
[(set (match_operand:SI 0 "s_register_operand" "=Ts,Ts,Ts")
(if_then_else:SI
diff --git a/gcc/testsuite/gcc.target/arm/csneg.c
b/gcc/testsuite/gcc.target/arm/csneg.c
new file mode 100644
index 00000000000..e48606265af
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arm/csneg.c
@@ -0,0 +1,33 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target arm_arch_v8_1m_main_ok } */
+/* { dg-options "-O2 -march=armv8.1-m.main" } */
+
+int
+test_csneg32_condasn1(int w0, int w1, int w2, int w3)
+{
+ int w4;
+
+ /* { dg-final { scan-assembler "csneg\tr\[0-9\]*.*ne" } } */
+ w4 = (w0 == w1) ? -w2 : w3;
+ return w4;
+}
+
+int
+test_csneg32_condasn2(int w0, int w1, int w2, int w3)
+{
+ int w4;
+
+ /* { dg-final { scan-assembler "csneg\tr\[0-9\]*.*eq" } } */
+ w4 = (w0 == w1) ? w3 : -w2;
+ return w4;
+}
+
+unsigned long long
+test_csneg_uxtw (unsigned int a, unsigned int b, unsigned int c)
+{
+ unsigned int val;
+
+ /* { dg-final { scan-assembler "csneg\tr\[0-9\]*.*ne" } } */
+ val = a ? b : -c;
+ return val;
+}
csel_4.patch
Description: csel_4.patch
