Fix broken GemmRewriteTest.BF16GemmCodeGen on Hopper.

This was broken by openxla@4e09e73.

The issue is that the optimized HLO was changed by having a native BF16 multiply, so the filecheck string had to be changed. Because the multiply is done in BF16 instead of FP32, the tolerance must also be lowered.

PiperOrigin-RevId: 616380852

Author: reedwm

xla/service/gpu/tests/gemm_rewrite_test.cc

@@ -257,18 +257,32 @@ ENTRY bf16gemm {
 }
   )";
 
-  MatchOptimizedHlo(hlo_text, R"(
-; CHECK:  [[P1:%[^ ]+]] = bf16[3]{0} parameter(1)
-; CHECK:  [[INSTR_1:%[^ ]+]] = f32[3]{0} convert([[P1]])
-; CHECK:  [[P0:%[^ ]+]] = bf16[3]{0} parameter(0)
-; CHECK:  [[INSTR_3:%[^ ]+]] = f32[3]{0} convert([[P0]])
-; CHECK:  [[INSTR_4:%[^ ]+]] = f32[3]{0} multiply([[INSTR_1]], [[INSTR_3]])
-; CHECK:  [[INSTR_5:%[^ ]+]] = f32[] constant(0)
-; CHECK:  [[INSTR_6:%[^ ]+]] = f32[] reduce([[INSTR_4]], [[INSTR_5]]), dimensions={0}, to_apply=[[INSTR_7:%[^ ]+]]
-; CHECK:  ROOT [[INSTR_8:%[^ ]+]] = bf16[] convert([[INSTR_6]])
-  )");
+  if (CudaOrRocmCheck(9, 0, Switch::False)) {
+    // The Hopper optimized HLO has a BF16 multiply instruction since Hopper has
+    // native BF16 multiply support.
+    MatchOptimizedHlo(hlo_text, R"(
+  ; CHECK:  [[P0:%[^ ]+]] = bf16[3]{0} parameter(0)
+  ; CHECK:  [[P1:%[^ ]+]] = bf16[3]{0} parameter(1)
+  ; CHECK:  [[INSTR_2:%[^ ]+]] = bf16[3]{0} multiply([[P0]], [[P1]])
+  ; CHECK:  [[INSTR_3:%[^ ]+]] = f32[3]{0} convert([[INSTR_2]])
+  ; CHECK:  [[INSTR_4:%[^ ]+]] = f32[] constant(0)
+  ; CHECK:  [[INSTR_5:%[^ ]+]] = f32[] reduce([[INSTR_3]], [[INSTR_4]]), dimensions={0}, to_apply=[[INSTR_6:%[^ ]+]]
+  ; CHECK:  ROOT [[INSTR_7:%[^ ]+]] = bf16[] convert([[INSTR_5]])
+    )");
+  } else {
+    MatchOptimizedHlo(hlo_text, R"(
+  ; CHECK:  [[P1:%[^ ]+]] = bf16[3]{0} parameter(1)
+  ; CHECK:  [[INSTR_1:%[^ ]+]] = f32[3]{0} convert([[P1]])
+  ; CHECK:  [[P0:%[^ ]+]] = bf16[3]{0} parameter(0)
+  ; CHECK:  [[INSTR_3:%[^ ]+]] = f32[3]{0} convert([[P0]])
+  ; CHECK:  [[INSTR_4:%[^ ]+]] = f32[3]{0} multiply([[INSTR_1]], [[INSTR_3]])
+  ; CHECK:  [[INSTR_5:%[^ ]+]] = f32[] constant(0)
+  ; CHECK:  [[INSTR_6:%[^ ]+]] = f32[] reduce([[INSTR_4]], [[INSTR_5]]), dimensions={0}, to_apply=[[INSTR_7:%[^ ]+]]
+  ; CHECK:  ROOT [[INSTR_8:%[^ ]+]] = bf16[] convert([[INSTR_6]])
+    )");
+  }
 
-  EXPECT_TRUE(RunAndCompare(hlo_text, ErrorSpec{1e-5, 1e-5}));
+  EXPECT_TRUE(RunAndCompare(hlo_text, ErrorSpec{1e-4, 1e-4}));
 }
 
 TEST_F(GemmRewriteTest, BF16Transpose) {