diff mbox series

[v2] MATCH: Simplify `(trunc)copysign ((extend)x, CST)` to `copysign (x, -1.0/1.0)` [PR112472]

Message ID 20241016161844.1672-1-quic_eikagupt@quicinc.com
State New
Headers show
Series [v2] MATCH: Simplify `(trunc)copysign ((extend)x, CST)` to `copysign (x, -1.0/1.0)` [PR112472] | expand

Commit Message

Eikansh Gupta Oct. 16, 2024, 4:18 p.m. UTC 
This patch simplify `(trunc)copysign ((extend)x, CST)` to `copysign (x, -1.0/1.0)`
depending on the sign of CST. Previously, it was simplified to `copysign (x, CST)`.
It can be optimized as the sign of the CST matters, not the value.

The patch also simplify `(trunc)abs (extend x)` to `abs (x)`.

	PR tree-optimization/112472

gcc/ChangeLog:

	* match.pd ((trunc)copysign ((extend)x, -CST) --> copysign (x, -1.0)): New pattern.
	((trunc)abs (extend x) --> abs (x)): New pattern.

gcc/testsuite/ChangeLog:

	* gcc.dg/tree-ssa/pr112472.c: New test.

Signed-off-by: Eikansh Gupta <quic_eikagupt@quicinc.com>
---
 gcc/match.pd                             | 20 +++++++++++++++++---
 gcc/testsuite/gcc.dg/tree-ssa/pr112472.c | 22 ++++++++++++++++++++++
 2 files changed, 39 insertions(+), 3 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/tree-ssa/pr112472.c
diff mbox series

Patch

diff --git a/gcc/match.pd b/gcc/match.pd
index 940292d0d49..a1668c4c9dc 100644
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -8527,15 +8527,29 @@  DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    x,y is float value, similar for _Float16/double.  */
 (for copysigns (COPYSIGN_ALL)
  (simplify
-  (convert (copysigns (convert@2 @0) (convert @1)))
+  (convert (copysigns (convert@2 @0) (convert2? @1)))
    (if (optimize
        && !HONOR_SNANS (@2)
        && types_match (type, TREE_TYPE (@0))
-       && types_match (type, TREE_TYPE (@1))
        && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@2))
        && direct_internal_fn_supported_p (IFN_COPYSIGN,
 					  type, OPTIMIZE_FOR_BOTH))
-    (IFN_COPYSIGN @0 @1))))
+    (if (types_match (type, TREE_TYPE (@1)))
+     (IFN_COPYSIGN @0 @1)
+     /* (trunc)copysign (extend)x, CST) to copysign (x, -1.0/1.0) */
+     (if (REAL_VALUE_NEGATIVE (TREE_REAL_CST (@1)))
+      (IFN_COPYSIGN @0 { build_minus_one_cst (type); })
+      (IFN_COPYSIGN @0 { build_one_cst (type); }))))))
+
+/* (trunc)abs (extend x) --> abs (x)
+   x is a float value */
+(simplify
+ (convert (abs (convert@1 @0)))
+  (if (optimize
+      && !HONOR_SNANS (@1)
+      && types_match (type, TREE_TYPE (@0))
+      && TYPE_PRECISION (type) < TYPE_PRECISION (TREE_TYPE (@1)))
+   (abs @0)))
 
 (for froms (BUILT_IN_FMAF BUILT_IN_FMA BUILT_IN_FMAL)
      tos (IFN_FMA IFN_FMA IFN_FMA)
diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr112472.c b/gcc/testsuite/gcc.dg/tree-ssa/pr112472.c
new file mode 100644
index 00000000000..8f97278ffe8
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr112472.c
@@ -0,0 +1,22 @@ 
+/* PR tree-optimization/109878 */
+/* { dg-do compile } */
+/* { dg-options "-O1 -fdump-tree-optimized" } */
+
+/* Optimized to .COPYSIGN(a, -1.0e+0) */
+float f(float a)
+{
+  return (float)__builtin_copysign(a, -3.0);
+}
+
+/* This gets converted to (float) abs((double) a)
+   With the patch it is optimized to abs(a) */
+float f2(float a)
+{
+  return (float)__builtin_copysign(a, 5.0);
+}
+
+/* { dg-final { scan-tree-dump-not "= __builtin_copysign" "optimized" } } */
+/* { dg-final { scan-tree-dump-not " double " "optimized" { target ifn_copysign } } } */
+/* { dg-final { scan-tree-dump-times ".COPYSIGN" 1 "optimized" { target ifn_copysign } } } */
+/* { dg-final { scan-tree-dump-times "-1.0e\\+0" 1 "optimized" { target ifn_copysign } } } */
+/* { dg-final { scan-tree-dump-times " ABS_EXPR " 1 "optimized" { target ifn_copysign } } } */