On Mar 29, 2026, Alexandre Oliva <[email protected]> wrote:
> On Mar 29, 2026, Richard Biener <[email protected]> wrote:
>> Moving the test is OK.
> I'll split out that big, then.
g++.dg/alias-checks.C requires vect_double outside vect.exp, where
-msse2 would have got enabled, but that effective_target is not
supposed to be used in such circumstances: it passes even when SSE2 is
disabled. Without enabling SSE2, vectors of doubles aren't really
available, so we don't get the expected vectorizations and the test
fails.
Instead of adding machine-specific options to alias-checks.C, I'm
moving it under g++.dg/vect/ and renaming it so that it gets, and
doesn't override, the default vector options for each platform.
Regstrapped on x86_64-linux-gnu. Also tested with ppc-elf and
ppc-vx7r2. I'm going to put it in in the not-too-distant future ;-)
for gcc/testsuite/ChangeLog
* g++.dg/alias-checks.C: Rename to...
* g++.dg/vect/vect-alias-checks.C: ... this. Don't override
vector options.
---
gcc/testsuite/g++.dg/alias-checks.C | 86 -------------------------
gcc/testsuite/g++.dg/vect/vect-alias-checks.C | 86 +++++++++++++++++++++++++
2 files changed, 86 insertions(+), 86 deletions(-)
delete mode 100644 gcc/testsuite/g++.dg/alias-checks.C
create mode 100644 gcc/testsuite/g++.dg/vect/vect-alias-checks.C
diff --git a/gcc/testsuite/g++.dg/alias-checks.C
b/gcc/testsuite/g++.dg/alias-checks.C
deleted file mode 100644
index b8ff3ad605c23..0000000000000
--- a/gcc/testsuite/g++.dg/alias-checks.C
+++ /dev/null
@@ -1,86 +0,0 @@
-
-// { dg-do compile }
-// { dg-require-effective-target c++17 }
-// { dg-require-effective-target vect_double }
-// { dg-options "-O3 -fdump-tree-vect-all" }
-// { dg-skip-if "required hosted libstdc++ for cmath and iostream" { !
hostedlib } }
-
-#include <cstdlib>
-#include <cmath>
-#include <iostream>
-void DoIfClause(double *l, double *r, const double *m2, const double *m1,
- const double *c, const double *p1, const double *p2, int istart, int
iend)
-{
- constexpr double w5alpha[3][3] = {{1.0 / 3.0, -7.0 / 6.0, 11.0 / 6.0},
- {-1.0 / 6.0, 5.0 / 6.0, 1.0 / 3.0},
- {1.0 / 3.0, 5.0 / 6.0, -1.0 / 6.0}};
- constexpr double w5gamma[3] = {0.1, 0.6, 0.3};
- constexpr double eps = 1e-100;
- constexpr double thirteen_thirds = 13.0 / 3.0;
-
- for (int i = istart; i <= iend; ++i) {
- const double q0 = m2[i];
- const double q1 = m1[i];
- const double q2 = c[i];
- const double q3 = p1[i];
- const double q4 = p2[i];
- double &ql = l[i];
- double &qr = r[i];
- double a = q0 - 2 * q1 + q2;
- double b = q0 - 4.0 * q1 + 3.0 * q2;
- double beta0 = thirteen_thirds * a * a + b * b + eps;
- a = q1 - 2.0 * q2 + q3;
- b = q3 - q1;
- double beta1 = thirteen_thirds * a * a + b * b + eps;
- a = q2 - 2.0 * q3 + q4;
- b = q4 - 4.0 * q3 + 3.0 * q2;
- double beta2 = thirteen_thirds * a * a + b * b + eps;
- const double tau5 = std::abs(beta2 - beta0);
-
- beta0 = (beta0 + tau5) / beta0;
- beta1 = (beta1 + tau5) / beta1;
- beta2 = (beta2 + tau5) / beta2;
-
- double w0 = w5gamma[0] * beta0 + eps;
- double w1 = w5gamma[1] * beta1 + eps;
- double w2 = w5gamma[2] * beta2 + eps;
- double wsum = 1.0 / (w0 + w1 + w2);
- ql = w0 * (w5alpha[0][0] * q0 + w5alpha[0][1] * q1 + w5alpha[0][2] *
q2);
- ql += w1 * (w5alpha[1][0] * q1 + w5alpha[1][1] * q2 + w5alpha[1][2] *
q3);
- ql += w2 * (w5alpha[2][0] * q2 + w5alpha[2][1] * q3 + w5alpha[2][2] *
q4);
- ql *= wsum;
- const double alpha_l = 3.0 * wsum * w0 * w1 * w2 /
- (w5gamma[2] * w0 * w1 + w5gamma[1] * w0 * w2 +
- w5gamma[0] * w1 * w2) +
- eps;
-
- w0 = w5gamma[0] * beta2 + eps;
- w1 = w5gamma[1] * beta1 + eps;
- w2 = w5gamma[2] * beta0 + eps;
- wsum = 1.0 / (w0 + w1 + w2);
- qr = w0 * (w5alpha[0][0] * q4 + w5alpha[0][1] * q3 + w5alpha[0][2] *
q2);
- qr += w1 * (w5alpha[1][0] * q3 + w5alpha[1][1] * q2 + w5alpha[1][2] *
q1);
- qr += w2 * (w5alpha[2][0] * q2 + w5alpha[2][1] * q1 + w5alpha[2][2] *
q0);
- qr *= wsum;
- const double alpha_r = 3.0 * wsum * w0 * w1 * w2 /
- (w5gamma[2] * w0 * w1 + w5gamma[1] * w0 * w2 +
- w5gamma[0] * w1 * w2) +
- eps;
-
- double dq = q3 - q2;
- {
- const double dm = q2 - q1;
- const double dp = dq;
- const double dc = (dm * dp > 0.0) * 0.5 * (dm + dp);
- dq = 0.5 * std::copysign(
- std::min(std::fabs(dc),
- 2.0 * std::min(std::fabs(dm), std::fabs(dp))),
- dc);
- }
-
- const double alpha_lin = 2.0 * alpha_l * alpha_r / (alpha_l + alpha_r);
- ql = alpha_lin * ql + (1.0 - alpha_lin) * (q2 + dq);
- qr = alpha_lin * qr + (1.0 - alpha_lin) * (q2 - dq);
- }
-}
-/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
diff --git a/gcc/testsuite/g++.dg/vect/vect-alias-checks.C
b/gcc/testsuite/g++.dg/vect/vect-alias-checks.C
new file mode 100644
index 0000000000000..97c97d2c99e0d
--- /dev/null
+++ b/gcc/testsuite/g++.dg/vect/vect-alias-checks.C
@@ -0,0 +1,86 @@
+
+// { dg-do compile }
+// { dg-require-effective-target c++17 }
+// { dg-require-effective-target vect_double }
+// { dg-additional-options "-O3 -fdump-tree-vect-all" }
+// { dg-skip-if "required hosted libstdc++ for cmath and iostream" { !
hostedlib } }
+
+#include <cstdlib>
+#include <cmath>
+#include <iostream>
+void DoIfClause(double *l, double *r, const double *m2, const double *m1,
+ const double *c, const double *p1, const double *p2, int istart, int
iend)
+{
+ constexpr double w5alpha[3][3] = {{1.0 / 3.0, -7.0 / 6.0, 11.0 / 6.0},
+ {-1.0 / 6.0, 5.0 / 6.0, 1.0 / 3.0},
+ {1.0 / 3.0, 5.0 / 6.0, -1.0 / 6.0}};
+ constexpr double w5gamma[3] = {0.1, 0.6, 0.3};
+ constexpr double eps = 1e-100;
+ constexpr double thirteen_thirds = 13.0 / 3.0;
+
+ for (int i = istart; i <= iend; ++i) {
+ const double q0 = m2[i];
+ const double q1 = m1[i];
+ const double q2 = c[i];
+ const double q3 = p1[i];
+ const double q4 = p2[i];
+ double &ql = l[i];
+ double &qr = r[i];
+ double a = q0 - 2 * q1 + q2;
+ double b = q0 - 4.0 * q1 + 3.0 * q2;
+ double beta0 = thirteen_thirds * a * a + b * b + eps;
+ a = q1 - 2.0 * q2 + q3;
+ b = q3 - q1;
+ double beta1 = thirteen_thirds * a * a + b * b + eps;
+ a = q2 - 2.0 * q3 + q4;
+ b = q4 - 4.0 * q3 + 3.0 * q2;
+ double beta2 = thirteen_thirds * a * a + b * b + eps;
+ const double tau5 = std::abs(beta2 - beta0);
+
+ beta0 = (beta0 + tau5) / beta0;
+ beta1 = (beta1 + tau5) / beta1;
+ beta2 = (beta2 + tau5) / beta2;
+
+ double w0 = w5gamma[0] * beta0 + eps;
+ double w1 = w5gamma[1] * beta1 + eps;
+ double w2 = w5gamma[2] * beta2 + eps;
+ double wsum = 1.0 / (w0 + w1 + w2);
+ ql = w0 * (w5alpha[0][0] * q0 + w5alpha[0][1] * q1 + w5alpha[0][2] *
q2);
+ ql += w1 * (w5alpha[1][0] * q1 + w5alpha[1][1] * q2 + w5alpha[1][2] *
q3);
+ ql += w2 * (w5alpha[2][0] * q2 + w5alpha[2][1] * q3 + w5alpha[2][2] *
q4);
+ ql *= wsum;
+ const double alpha_l = 3.0 * wsum * w0 * w1 * w2 /
+ (w5gamma[2] * w0 * w1 + w5gamma[1] * w0 * w2 +
+ w5gamma[0] * w1 * w2) +
+ eps;
+
+ w0 = w5gamma[0] * beta2 + eps;
+ w1 = w5gamma[1] * beta1 + eps;
+ w2 = w5gamma[2] * beta0 + eps;
+ wsum = 1.0 / (w0 + w1 + w2);
+ qr = w0 * (w5alpha[0][0] * q4 + w5alpha[0][1] * q3 + w5alpha[0][2] *
q2);
+ qr += w1 * (w5alpha[1][0] * q3 + w5alpha[1][1] * q2 + w5alpha[1][2] *
q1);
+ qr += w2 * (w5alpha[2][0] * q2 + w5alpha[2][1] * q1 + w5alpha[2][2] *
q0);
+ qr *= wsum;
+ const double alpha_r = 3.0 * wsum * w0 * w1 * w2 /
+ (w5gamma[2] * w0 * w1 + w5gamma[1] * w0 * w2 +
+ w5gamma[0] * w1 * w2) +
+ eps;
+
+ double dq = q3 - q2;
+ {
+ const double dm = q2 - q1;
+ const double dp = dq;
+ const double dc = (dm * dp > 0.0) * 0.5 * (dm + dp);
+ dq = 0.5 * std::copysign(
+ std::min(std::fabs(dc),
+ 2.0 * std::min(std::fabs(dm), std::fabs(dp))),
+ dc);
+ }
+
+ const double alpha_lin = 2.0 * alpha_l * alpha_r / (alpha_l + alpha_r);
+ ql = alpha_lin * ql + (1.0 - alpha_lin) * (q2 + dq);
+ qr = alpha_lin * qr + (1.0 - alpha_lin) * (q2 - dq);
+ }
+}
+/* { dg-final { scan-tree-dump "LOOP VECTORIZED" "vect" } } */
--
Alexandre Oliva, happy hacker https://blog.lx.oliva.nom.br/
Free Software Activist FSFLA co-founder GNU Toolchain Engineer
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